In contrast, shrinking ribociclib-sensitive tumors retained more persistent communications with cytotoxic CD8 + T cells, with stronger signals from fibroblasts and cancer cells (Fig. 3C top right panels) (Discovery: est = 0.16, z = 13.03, p < 0.0001, Validation: est=0.05, z = 3.24, p < 0.00001) (Figure S7B). Here, CD8A is linked to cancer.