KRAS and colorectal carcinoma: Among stage II and III CRC, there were studies found KRAS mutation would worsen the OS (Richman et al., 2009) or disease-free survival (DFS) (Deng et al., 2015; Lee et al., 2015) of patients while other study found KRAS mutation was not associated with the OS or recurrence-free survival (RFS) of CRC patients (Roth et al., 2010).