Hepatosplenomegaly and/or lymphadenopathy was mainly found in the patients with LCH, metabolic diseases (such as MMA and Niemann-Pick disease (NPD)), PID associated ILD (such as CVID, CTLA4 deficiency, ALPS and CGD) and malignant infiltrates. The gene discussed is CTLA4; the disease is autoimmune lymphoproliferative syndrome.