CD8A and neoplasm: We associate the expansion of tumor antigen–specific CD8+ T cells after short-course ATRi plus RT (Figure 1) with both the potentiation of RT-induced tumor inflammation (Figure 4) and innate immune activity (Figure 5) by ATRi as well as the independent effects of ATRi on T cells and the proliferative rebound that follows cessation of ATRi (Figures 2 and 3).