The parents of four boys with a life-threatening illness are waiting to hear if a bone marrow transplant has proved successful for a second son.
Doctors are waiting to see if Daniel's treatment has worked
Josh, Nathan, Daniel and Luke Hartley were born with an extremely rare genetic disorder which attacks the immune system.
A nationwide appeal for donors earlier this year drew thousands of responses.
But the family are renewing their appeal, as their two remaining sons still need a bone marrow transplant.
There are only about a hundred people in the world who have been diagnosed with X-Linked Lymphoproliferative Syndrome (XLP) or Duncan Disease -- including the four Hartley brothers.
People with the condition rarely live into their teens, but a bone marrow transplant can provide a cure.
David Hartley, the boys' father, told the BBC that his eldest son Josh, who is 12, had a successful transplant in May.
Last week, eight year-old Daniel underwent the procedure.
For 10 days before the transplant he was given chemotherapy to dampen down the immune system.
Daniel then received the bone marrow transplant. The procedure does not require an operation.
Looking forward to school
Mr Hartley said he was dong very well and was in good spirits.
"We'll know in two to three weeks if it's worked, and hopefully Daniel will be home in the new year.
He added: "Daniel is great. I can't describe it any other way. He's very well.
"There was one day during chemo he was quite poorly, other than that he's picked up really well. He's in good spirits but there's a long way to go"
The boys will have a normal life expectancy if they can find donors
Doctors are "extremely hopeful" Daniel's treatment will be successful because the donor was a good match.
His brother Josh is still recovering from his transplant was in May.
By Mr Hartley said: "He's doing great. We hope he'll to be back at school by Christmas.
"He's fantastic, he's cured, he no longer has XLP. But it takes up to two years for a new immune system to catch up."
He said he was "so grateful" to the thousands of people who have came forward to help us.
"What really brought it home to us was that there are a hundred families at Great Ormond Street Hospital just waiting for that call; that they've found a match, and that's our call for action. Every donor who calls helps to increase that likelihood."
A spokesman for the Anthony Nolan Trust said: "We are delighted that the family all have donors now.
"David Hartley is still hoping to recruit more young male donors. There are 7,000 patients around the world still waiting to find a suitable bone marrow donor."
The hotline number for anyone interested in finding out how they could save a life is 0901 8822234.