PDGFRB and breast cancer: Overall, Lum breast cancer had higher percentage of aSMA expressing (statistically significant, χ2 = 16.14; df=1; p=5.9e-05) and PDGFRa (statistically not significant, χ2 = 1.59; df=1; p=0.21) expressing CAFs (Figures 5B and 6B; Supplementary Table 8) in contrast with TN breast cancer which had significantly higher percentage of PDGFRb+ (χ2 = 7.27; df=1; p=0.007) and slightly higher percentage of FAP+ CAFs (statistically not significant, χ2 = 0.51; df=1; p=0.47) when compared to Lum (Figures 5B and 6B; Supplementary Table 7).