BOYZONE'S Keith Duffy has made platinum-selling albums, sold out stadiums around the world and had a starring role in Coronation Street.
But last week his nine-year-old daughter gave him his proudest moment by simply blushing.
Mia is autistic. Her social skills are limited and her reactions different to 'normal' children's.
He says: "When the band got back together last year Mia learned all the songs and watched all the DVDs. She knows more Boyzone songs than me now.
"She developed a bit of a crush on Shane.
"All the band came to my house for the first time in ages last week. Mia walked in and as soon as she saw Shane she blushed.
"Now that might not seem much but to see my gorgeous girl react so normally made me more proud than any father in the world.
"It meant we had come so far with her. It was the cutest, most beautiful thing to witness. She is our mini-miracle."
Keith is running the London Marathon on Sunday in aid of the National Autisism Society.
His passionate fundraising has raked in more than £3.5million in Ireland and he now hopes to roll out the programme he has helped introduce in his home country in the UK.
The singer turned actor and his wife Lisa, who also have a son, Jordan, 14, realised something was wrong when Mia was 18 months old.
He says: "She wasn't responding to us. We thought she had a hearing problem because her brother had needed gromits.
"When she was tested her hearing was perfect and we realised we were dealing with something more serious.
"It was very difficult to get a diagnosis because we were put on waiting lists everywhere. Through my job I managed to fast track her.
"We managed to get her diagnosed at 22 and a half months."
When they were eventually told what was wrong the news was devastating.
Keith says: "We were given the word but we had no idea what it meant or what to do next or where we had to go.
"Like most people in the world the first thing I thought about was Rain Man the Dustin Hoffman film but that didn't sound like my daughter. I realised later that is a very bad example of someone with austism.
"I had to get back to basics and realise it was a developmental disability that effects progression in different ways. Different autistic children can have different levels of speech, and motor skills, and social skills, and behavioural problems.
"Mia had difficulty socialising and she didn't speak until she was six."
The shockwaves hit the whole family.
Keith says: "Lisa went into denial for the first year. I felt huge frustration that I couldn't keep my wife happy and that I couldn't help my daughter because I couldn't understand her disability.
"I channelled that into fundraising. I was trying to sort the masses out while forgetting I had my own issues at home.
"Charity work did help me get through a difficult time. But then I realised I had to get my wife's head out of the sand and we had to help Mia together.
"'We had some very, very difficult months in our own relationship.
"'Thank God we came out the other side."
The Duffys organised Applied Behaviour Analysis (ABA) for Mia.
Keith says: "That's an American system that people have been using for 30 years that has fantastic success rates. It's reinforcing positive skills and play through rewards.
"It's given us a mini-miracle with our own daughter.
"She was in a special needs school for the first five years with one to one teaching.
"They started to integrate her into mainstream just 20 minutes a week, then that built up to an hour a week, then a day, two days, all with a special needs assistant with her.
"She then went full time in the school with an assistant and after six months we decided it was time for her to stand on her own two feet and do without the assistant and she's now been doing that for 18 months.
"To us that is the most incredible achievement."
He adds: "Mia now is the most wonderful, beautiful, happy, smiling little girl you've ever met in your life. She speaks with an American accent because she didn't speak until she was nearly six and she picked up her speech from American TV shows like Barney.
"She can sound a little bit robotic but we're just delighted that she can communicate.
"The fact she can ask for things she wants is a great frustration gone from our lives. If she couldn't tell us what she wanted and that could make her go further inside herself where we couldn't reach her.
"For a lot of years I missed out on the affection from the Daddy's girl relationship. Mia was unable to give that and if she did she gave it to her Mum.
"Now I do have that relationship with her and I get the odd hug and kiss.
"Every day is still a challenge but you keep trying to go forward with her."
Keith is determined to use his music and acting to achieve the same incredible results for other families.
He says: "I knew someone in the music business who had a daughter with autism. He advised us what to do. Between us and with some other parents we started Irish Autism Action.
"If I can use my fame to kick the a***s of people in power to get services for children in all postal codes rather than just some then I will.
'We've put in place early intervention for diagnosis and one to one applied behavioural analysis.
"Early diagnosis is essential for the child but trying to get that through the NHS or here in Ireland is almost impossible. It can take anything from 18 to 24 months which are crucial months in that child's development - you will never get them back.
"We went to the root of the problem and opened up our own diagnostic and assessment centre in Ireland. We've diagnosed 300 children in Ireland and helped 300 families.
"We have 13 schools around the country educating 400 autistic children. Every child is affected completely differently so they have to have individual plans and one to one teaching.
"We have full-time staff running a 24-hour helpline. It's all completely funded by us."
Even that's not enough for Keith.
He says: "However great that might all sound we still have a waiting list for maybe 100 children at each school which is not acceptable.
"I want to help families in the UK and let them know there is light at the end of the tunnel. If autistic children get the right intervention and care they can progress much better than they have been allowed to in the past.
"I love my daughter, I want to make her life as good as it can possibly be and I am passionate about helping other families too. These children need to be championed. People need to realise they are just as important as any normally developing child.
"It's up to us parents to make sure the awareness is out there.
"I want people to educate themselves to children's disability. People can be incredibly ignorant about disability. If a child with autism is having sensory issues in a supermarket and throwing a tantrum instead of judging the parents people should think about what be causing that behaviour. Autism doesn't show itself like Down's Syndrome for example."
So on Sunday when Keith makes it across the finish line with bandmate Ronan Keating - who's running alongside him - his first thoughts will be of his Mia.
"All I can hope for her is that each day is good," he says.
"I don't look at ten or even five years down the road because right now she's flying. I don't know if she'll be able to attend a mainstream secondary school. I really don't know which way her disability is going to take her and us.
"All Lisa and I can think is: 'today is a good day, let's hope tomorrow is even better.'"
- To sponsor Keith go to: www.justgiving.com/keithduffy