KRAS and colorectal carcinoma: As for elderly patients, a different incidence of KRAS mutation has been reported according to the microsatellite status of the tumor; indeed, in this population, KRAS mutation seems to be more frequent in the case of microsatellite-stable MSS CRC, especially in males, whereas it seems to be lower in microsatellite-unstable tumors or with high mutational burden [84,85].