Kikuchi-Fujimoto Disease, also known as histiocytic necrotizing lymphadenitis, is related to antiphospholipid syndrome and vasculitis. An important gene associated with Kikuchi-Fujimoto Disease is C1S (Complement C1s), and among its related pathways/superpathways is Diseases of hemostasis. Affiliated tissues include lymph node and bone, and related phenotypes are cervical lymphadenopathy and fatigue