SOX17 and cancer: SOX17 has been implicated as a tumor suppressor gene in various solid tumors [22, 30, 36, 37], and we argue that the mutations we detected occur because of cancer-specific selection rather than mutational noise because of the small size of the gene, the paucity of SOX17 mutations in POLE-mutated tumors and the lack of strand-slippage mutations in MSI tumors.