KRAS and colorectal carcinoma: With reference to KRAS sub-type mutation in stage IV CRC patients, high homogeneity (all I2 = 0%) between studies and pooled ORs was observed with 0.55 (95% CI; 0.35, 0.88) for KRAS codon12+13 mutation, 0.69 (95% CI; 0.43, 1.11) for KRAS codon12 mutation, and 0.59 (95% CI; 0.21, 1.64) for KRAS codon13 mutation.