APEX1 and cancer: Polymorphisms of MLH1, APEX1, MUTYH, OGG1, NUDT1, and XRCC5 are associated with sporadic CRC (Kim et al., 2004; Lai et al., 2016; Yang et al., 2009) and other site‐specific cancers (Li et al., 2011; Savina et al., 2016; Smith et al., 2011).