WASP is indispensable for normal leukocyte function and its importance is highlighted in the congenital disorder Wiskott–Aldrich syndrome in which missense mutations in the WAS gene result in severe immunodeficiency (Derry et al., 1994; Ochs and Thrasher, 2006; Thrasher and Burns, 2010). This evidence concerns the gene WAS and Immunodeficiency.