SH2D1A and hemophagocytic syndrome: Furthermore, the mutations in SLAM-associated protein (SAP) and X-linked inhibitor of apoptosis that result in X-linked lymphoproliferative diseases (XLP) 1 and 2 affect many lymphocytes and also result in fulminant IM and HLH (49–53), even so also NKT cell development is compromised in XLP1 patients (54, 55).