A life-saving transplant for the second of four brothers with one of the world's rarest fatal illnesses is proving successful, doctors say.
Daniel was treated at Great Ormond Street Hospital in London
Tests on eight-year-old Daniel Hartley show his immune system is rebuilding itself after a bone-marrow transplant.
Daniel and his brothers Josh, Nathan, and Luke, from Romsey, Hants, have the extremely rare genetic disorder XLP, which attacks the immune system.
His parents are still looking for donor matches for Luke and Nathan.
The four boys were diagnosed with the genetic defect known as X-Linked Lymphoproliferative Syndrome, or Duncan's Syndrome, in November 2003.
Elder brother Josh, 12, was successfully treated with a bone-marrow transplant from his mother Allison Hartley in the summer.
After Daniel's operation last week, tests showed his body is beginning to produce white blood cells - a sign that the transplant has been accepted.