BRAF and colorectal carcinoma: 34,46,48 Aberrant retention of presumed mutant nuclear p53 was rarely observed in the present series, although it occurred more frequently in serrated polyps with dysplasia (12%) than in adenomas (1%). One of the polyps with aberrant expression of p53 was a mixed polyp with BRAF mutation (Figure 1B). Had it not been removed, this polyp may have progressed within a short time frame to the subset of CRC with BRAF mutation, DNA methylation, TP53 mutation and DNA microsatellite stable status (a ‘fusion’ pathway shown in Table 3).49,50