“…Of the 17 studies that assessed the association between CD34 + cell yield and donor gender 12 (71%) reported higher CD34+ cell yields in males (9, 10, 12, 14, 17–19, 25, 28, 30, 43, 44) but the remaining five studies (29%) found no association (6, 15, 16, 24, 29). Of the 20 studies that assessed blood CD34+ cell concentration, eight (42%) reported higher concentrations in males (9, 30, 32, 34, 36, 37, 39, 45) whereas 12 (59%) reported no significant effect of gender (6, 17, 21, 22, 31, 33, 35, 38, 40–42, 46).…”