RIPK1 and cancer: Hypoxia has been implicated to promote cancer progression by activating adaptive transcriptional programs that promote cell survival and angiogenesis.27 Indeed, we found that exposure to hypoxia (1% O2) for 6 h reduced the expression of RIPK1 in the colon carcinoma cell lines HT29, HCT116, SW480, and Colo205 (Figure 2c).