Remarkably, in all BC subtypes, CD73 protein level was significantly higher in the stroma of CAF-S1-enriched tumors (median CD73 Hscore = 169) compared to CAF-S2- (median Hscore = 32.5) or CAF-S4-enriched (median Hscore = 73) BC (Figure 1D), thereby showing that CD73 accumulates in CAF-S1 fibroblasts in BC, as observed at mRNA levels [19] (Supplementary Figure S1C). Here, NT5E is linked to breast cancer.