CDK4 and colon adenocarcinoma: Since E2F signaling serves as an indicator of CDK4/6 activity, we performed a Pearson correlation test on some of the HIF1α and E2F target genes using the GEPIA tool based on TCGA colon adenocarcinoma data, and found weak correlations between the expression of some HIF1α and E2F targets (Supplementary Fig. S13, S14), which suggests that CDK4/6 activity may be associated with HIF1α signaling in patient tumors.