For the carcinomas located in the proximal colon, the multivariate analysis indicated that MLH1 negativity (OR = 0.39, 95%CI, p = 0.034), BRAF mutations (OR = 0.37, 95%CI, p = 0.0045), absence of K-ras mutation (OR = 0.34, 95%CI, p = 0.0012) and MSI (OR = 1.24, 95%CI, p = 0.019) presented an independent correlation with the CK7 positivity. The gene discussed is BRAF; the disease is carcinoma.