As in vivo experiments using cell lines do not depict the clinical heterogeneity of BCP-ALL patients, we next tested CD19-TRAIL in patient-derived BCP-ALL xenografts (PDX) from four patients (Patients 1–4, Supplementary Table S1, n = 5 PDX mice/group). The gene discussed is TNFSF10; the disease is acute lymphoblastic leukemia.