He has never met her, yet he will go under the knife today so that a 10-year-old child will have a chance to live a normal life.
The unnamed man is the second person in Singapore to donate part of his liver to a total stranger. The first, cabby Tong Ming Ming, volunteered part of his organ to civil servant Toh Lai Keng in March last year.
Phyllis Poh, a Primary 5 pupil at Bedok Green Primary School, found a donor after her older brother, Skye, expressed a wish to The Straits Times in November that someone would give an organ to her. Two men came forward, and one of them, who is in his 40s, was a match.
Skye, 12, himself had a liver transplant from his mother in February last year. He went on to complete his Primary School Leaving Examination (PSLE) the same year, though he missed months of school.
Both he and Phyllis suffer from a rare disease that causes their livers to fail or become cancerous, as well as their growth to be stunted.
Their mother, Madam Joanne Ng, 36, a housewife, could not also donate part of her liver to Phyllis, much as she wanted to. Their father, who operates a food stall, is not a match.
Skye found himself in the news when the PSLE results were released, and he took the chance to voice his wish for his sister to find a donor.
Liver transplants from living donors are not as common as kidney transplants, as they carry a higher risk. Last year, there were 12 living liver donors here, compared with 34 for kidney.
A very excited Phyllis said yesterday: "I want to meet the uncle and say thank you and wish him a speedy recovery."
Under organ transplant rules here, the donor and recipient cannot meet before the transplant, but both parties have said they would like to meet, and will likely do so after they have recovered from surgery.
Meanwhile, Phyllis has made him a card, covered with stickers that she treasures specially because "you have given me part of your precious liver".
She entered National University Hospital (NUH) on Monday to prepare for surgery. Her fear was soothed by a thorough briefing from Skye, so she is now only "a little scared".
But more than that, the little girl, who because of her disease is shorter than her healthy seven- year-old sister, is looking forward to a more active life - like that which Skye now enjoys.
Skye has grown by more than 10cm since his transplant last year.
His mother donated her organ when he developed two nodules that doctors said could become cancerous if he did not have a new liver. Yesterday, she said: "I'm so very grateful that Singaporeans have such big hearts, to come forward like this."
Unlike kidney donation which is considered very safe, liver donation carries a higher risk of complications to the donor of 10 to 15 per cent, according to international figures, and the risk of death or a serious problem of 1 per cent.
A spokesman for NUH said the hospital has done close to 50 living donor liver transplants and "we have not had any deaths or serious complications".
Dr Alfred Kow from the National University Centre for Organ Transplantation will lead the team to get the liver, and Professor K. Prabhakaran, head of paediatric surgery at NUH, will transplant the liver into Phyllis.