CD8A and breast carcinoma: Furthermore, the fact that dormancy is never observed in 4T1 breast cancer is explained by the low number of such protective T cells in 4T1-bearing hosts (Fig. 3) and not by their transcriptional signature, since CD39+PD-1+CD8+ cells from 4T1 and 4T07 tumors did not show many differences (Supplementary Fig. 10b–d).