XRCC2 and endometrium neoplasm: The mutational gene set for the gastrointestinal and endometrial tumors predominantly includes DNA repair genes (hereafter repair set), in particular, base excision repair (XRCC1 and XRCC6), nucleotide excision repair (NER, ERCC1-6), mismatch repair (MSH2-4 and MSH6, MLH1, and MLH2), non-homologous end joining (PARP1 and BRCA1), and homologous recombination (RAD51, XRCC2, and XRCC3).