RAD51 and lip and oral cavity carcinoma: The expression of RAD51 in oral cancer tissues, determined by immunohistochemistry, was negatively correlated with PFS and OS, and the Kaplan–Meier survival curves showed that the low RAD51 expression group had better PFS and OS than the high RAD51 expression group with P values of 0.06 and 0.04, respectively (Fig. 1E H).