Pfajfer L, et al. - Considering the pleiotropic expression of WDR1, researchers investigated the extent to which it might control the lymphoid arm of the immune system in humans. In six patients belonging to three kindreds, novel homozygous and compound heterozygous WDR1 missense mutations were identified. These patients presented with respiratory tract infections, skin ulceration and stomatitis. WDR1 deficiency was noted to be associated with aberrant T-cell activation and B-cell development in addition to defective adhesion and motility of neutrophils and monocytes. Findings thereby suggest a novel role for WDR1 in adaptive immunity, highlighting WDR1 as a central regulator of actin turnover during the formation of the B-cell and T-cell immunological synapses.