PDCD1 and neoplasm: Furthermore, targeting USP7 has been demonstrated to enhance the infiltration and cytotoxic activity of CD8+ T cells within the TME, while concurrently suppressing the expression of PD-L1 in tumor cells, thereby enhancing the response to anti-PD-1/PD-L1 therapy (Dai et al., 2020; Wang Z. et al., 2021).