Immunodeficiency 18, also known as cd3-epsilon deficiency, is related to precursor t-cell acute lymphoblastic leukemia and leukemia. An important gene associated with Immunodeficiency 18 is CD3E (CD3 Epsilon Subunit Of T-Cell Receptor Complex), and among its related pathways/superpathways are Phospholipase-C Pathway and Actin Nucleation by ARP-WASP Complex. Affiliated tissues include bone marrow and bone, and related phenotypes are defective t cell proliferation and lymphopenia