All 10 samples from patients with familial hemophagocytic lymphohistiocytosis (FHL) type 3, including five obtained before and five obtained after the onset of disease, showed significant reductions in Munc13-4 levels compared to control samples (Fig. 4A and Fig. S2). The gene discussed is UNC13D; the disease is Familial hemophagocytic lymphohistiocytosis.