RIPK1 kinase activity was reported to be required for Smac mimetics and anticancer drug-induced apoptosis in acute lymphoblastic leukemia cells.35 In contrast to this report, neither Nec-1 nor GSK'840 protected Smac mimetic and irinotecan-induced cell death (Figure 4d). The gene discussed is RIPK1; the disease is acute lymphoblastic leukemia.