In Chinese CRC patients, Shen et al found that gender was the only factor that showed an obvious relationship with KRAS mutations (female 44.7% vs male 28.2%, P = 0.037) [15]; Liou et al reported more frequent KRAS mutations in females and in non-smokers, and KRAS and BRAF mutations were significantly associated with the proximal location of cancer [16]. This evidence concerns the gene KRAS and colorectal carcinoma.