To investigate the role of RIPK1 in tumor necroptosis, we first tested if the specific RIPK1 inhibitor, Necrostatin-1 (Nec-1), has any effect on tumor necroptosis in the MVT-1 mouse breast cancer model21,22 as others and our early studies showed that Nec-1 effectively blocks TNF-induced necroptosis in vivo1,23,24. The gene discussed is PCSK1; the disease is breast cancer.