RRM2 and cancer: It is very interesting that these mediating genes are more likely cancer type-specific as approximately 97.4% of genes are identified for a single cancer while only 2.6% (i.e., a total of 14 genes, including CD79A, HPN, CBFA2T3, TACC3, KIF18B, RRM2, CIDEC, GNG7, B3GNT8, APOL2, CBX7, APOBEC3G, APOL1, and PEX11G) are shared across distinct cancers (Fig 4F).