Immunodeficiency 40, also known as dock2 deficiency, is related to lymphopenia and omenn syndrome. An important gene associated with Immunodeficiency 40 is DOCK2 (Dedicator Of Cytokinesis 2), and among its related pathways/superpathways are Signal Transduction and Signaling by Rho GTPases. Affiliated tissues include bone marrow and bone, and related phenotypes are t lymphocytopenia and recurrent pneumonia