The relevance of infusing mature effector cells in cancer patients is also underscored in the αβT- and B-cell-depleted haploidentical hematopoietic stem cell transplantation (HSCT), in which leukemia relapses and infections are sharply reduced as compared to the HSCT setting with “purified” CD34+ cells, thanks to the co-infusion of mature γδT cells and NK cells (see below). This evidence concerns the gene CD34 and infection.