PCNA and neoplasm: In agreement, the expression of a Pol κ mutant with increased affinity for PCNA and the overexpression of Pol κ generate genomic instability and tumor formation (Bavoux et al., 2005a; 2005b; Bergoglio et al., 2002; Hoffmann and Cazaux, 2010; O-Wang et al., 2001; Jones et al., 2012).