MLH3 and cancer: Moreover, in seven cancer types (SKCM, CESC, UCEC, STAD, LUAD, BRCA, and COAD), EP300 was co-mutated with at least one of the seven genes (MLH1, MLH3, MSH2, MSH3, MSH6, PMS1, and PMS2) functioning in DNA mismatch repair (p < 0.05, OR > 2) (Figure 1D).