Consistent with previous findings in TCGA-CRC cases [39], we found APC and RNF43 truncating mutations mutually exclusive in J-CRC and in US-CRC (Fig. 1) with significant enrichment of RNF43 alterations, particularly G659 mutations, in MMR-deficient tumors (Additional file 1: Figure S2). This evidence concerns the gene RNF43 and colorectal carcinoma.