Consistent with the oncogenic functions of mutant p53, mice with OSCCs expressing the p53R172H GOF mutation developed higher metastasis rates than mice with loss-of-function (LOF) p53 deletion or with wild-type p53. Throughout oral cancer progression, pre-invasive and invasive lesions showed a gradual increase in T-cell infiltration, recruitment of immunosuppressive regulatory T-cells (Tregs), and induction of PD-1/PD-L1 immune checkpoint proteins. Here, PDCD1 is linked to lip and oral cavity carcinoma.