More insightful data on the underlying mechanisms of immunotherapeutic interventions on T-cell exhaustion imply that ICI and, particularly, anti-PD-1 therapy do not reverse the actual process of exhaustion but rather expand “stem-like” pools of proliferation-competent precursors of exhausted cells (Tpex), which are associated with enhanced tumor regression [10,11,12]. Here, PDCD1 is linked to neoplasm.