Prior to CART19 infusion and lymphodepletion, 22 patients (67%) presented some degree of dysgammaglobulinemia according to normal age-matched range levels, with the main disturbance combinations isolated being hypo-IgM (8 of 22) and hypo-IgG plus hypo-IgM (6 of 22). The gene discussed is CD40LG; the disease is dysgammaglobulinemia.