Fever, dyspnea, abdominal pain, nausea, vomiting, anorexiaHSM; no pharyngitis or palpable LNWBC 17K, L 68%; increased liver enzymes and ferritinEBV VCA IgG+ IgM+; EA Ab−; EBNA+; Histoplasma and Cryptococcus serum Ag−; hepatitis A/B/C virus serology panel negative; Toxo Ab NDBone marrow with increased T cells; CT chest with lung nodules, GGO, pleural effusion, and HSM. The gene discussed is CD40LG; the disease is Pleural effusion.