Sea-Blue Histiocyte Disease, also known as sea-blue histiocytosis, is related to splenomegaly and niemann-pick disease, type b. An important gene associated with Sea-Blue Histiocyte Disease is APOE (Apolipoprotein E), and among its related pathways/superpathways are Transport of inorganic cations/anions and amino acids/oligopeptides and Plasma lipoprotein assembly, remodeling, and clearance. Affiliated tissues include bone marrow and bone, and related phenotypes are splenomegaly and hepatomegaly