In multivariate logistic regression analysis, BRAFV600E (HR=5.983, 95% CI: 2.075-17.251, p=0.001) and tumor size > 5 cm (HR=1.989, 95% CI: 1.017-3.889, p=0.045) were independent risk factors for absent PMS2 expression. The gene discussed is PMS2; the disease is neoplasm.