Similar to results on disease-free survival, obesity (log-rank test: P = 0.036), tumor differentiation status (log-rank test: P < 0.001), lymph node metastasis (log-rank test: P < 0.001), TNM stage (log-rank test: P < 0.001), MSI(log-rank test: P < 0.001), KRAS(log-rank test: P = 0.014), BRAF(log-rank test: P = 0.003) and PIK3CA(log-rank test: P = 0.001) mutations were also proved to be prognostic factors for overall survival of patients with colorectal cancer. The gene discussed is PIK3CA; the disease is colorectal cancer.