Lymphopenia, also known as lymphocytopenia, is related to immunodeficiency 13 and bare lymphocyte syndrome, type ii. An important gene associated with Lymphopenia is RAC2 (Rac Family Small GTPase 2), and among its related pathways/superpathways are Innate Immune System and ERK Signaling. The drugs Gemcitabine and Angiotensin II have been mentioned in the context of this disorder. Affiliated tissues include bone marrow and t cells, and related phenotypes are Increased JFH-1 genotype 2a Hepatitis C virus (HCV) infection and homeostasis/metabolism