PDCD1 and cancer: The ability to pharmacologically induce TCF-1+ TSCM cells suggests that it is feasible to design vaccines to establish long-term prophylactic protection and for personalized cancer vaccines with the potential to overcome insensitivity to PD-1 blockade (D'Alise et al., 2022; Held et al., 2019; Lugli et al., 2020; Rojas et al., 2023; Siddiqui et al., 2019; Zhao et al., 2022).