CD27 and severe combined immunodeficiency: A host of patients with other diseases such as ALPS, CGD, CVID, and SCID, as well as variants in genes including BTK, CARMIL2, CD27, ITK, LRBA, MAGT1, NEMO, PIK3CD, RAG2, WAS, NLR genes, and STAT genes, have been implicated with possible HLH (92–94).