Moreover, CAF abundance in breast cancer mouse models, produced via transplantation of 4T07 or D2A1 cells into the mammary fat pad of BALB/c or NSG mice, was recently shown to positively correlate with immune checkpoint blockade resistance via suppression of CD8+ T cell infiltration [245], suggesting that the presence of CAFs has implications for immunotherapy sensitivity. This evidence concerns the gene CD8A and breast cancer.