Autoimmune lymphoproliferative syndrome IB (ALPS-FASL) is a disorder in which the body cannot properly regulate the number of immune system cells (lymphocytes). This results in the overproduction of lymphocytes, which build up and cause enlargement of the lymph nodes, liver and spleen. Affected individuals can have a variety of autoimmune disorders, most of which damage the blood cells; some of the autoimmune disorders associated with ALPS can also damage the kidneys, liver, eyes, nerves, or connective tissues. Other signs and symptoms may include skin rashes or inflammation of fat under the skin (panniculitis); joint pain (arthritis); inflammation of blood vessels (vasculitis); mouth sores; premature ovarian failure; and the development of neurological damage. ALPS-FASL is caused by mutations in the FAS ligand gene, and there have been few reported cases. Management may include steroids or other medications, blood transfusions, and/or splenectomy (removal of the spleen) depending on the severity of the disorder.