RAB31 and colorectal carcinoma: To address the specificity of somatic mutations affecting the EGFR 3′UTR polyA tract in MSI CRC, we evaluated in 10 MSI with EGFR mutations and 10 MSS CRC samples the frequency of mutations within two other 3′UTR polyA tracts sharing structure similar to that of the EGFR: a polyA(15) in RAB31 (member RAS oncogene family) and a polyA(14) in ATP6V1G1 (ATPase V1 subunit G1).