Autoimmune lymphoproliferative syndrome (ALPS) is a rare inherited disorder of apoptosis, most commonly due to mutations in the FAS (TNFRSF6) gene. It presents with chronic lymphadenopathy, splenomegaly, and symptomatic multilineage cytopenias in an otherwise healthy child. Unfortunately, these clinical findings are also noted in other childhood lymphoproliferative conditions, such as leukemia,...