XLP is characterized by severe immune dysregulation that presents with susceptibility to EBV‐triggered lymphoproliferative disease (EBV‐LPD) or hemophagocytic lymphohistiocytosis (HLH), lymphoma, and dysgammaglobulinemia.71, 72SH2D1A encodes the signaling lymphocyte activation molecule (SLAM)‐associated protein (SAP). Here, SH2D1A is linked to lymphoma.