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The search began to find the best bone marrow match. The ideal donor would also have a CCR5 gene mutation resistant to HIV.
CCR5 is a protein on the surface of an immune cell that acts as the door that HIV enters to infect the body, but about one per cent of the population, primarily of northern European descent, are deficient of this gene.
That means there is no door for the virus to enter, “and so the virus can't get into the cells,” said Dr. Mario Ostrowski, a clinician-scientist at St. Michael’s Hospital who co-led the case with Walmsley. The new donor cells could also attack and eliminate the reservoir of virus-infected cells.












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