COL1A1 and breast cancer: A single-cell atlas study in BC identified CAFs from other cell types using markers PDGFRA and COL1A1 and clustered them into five subgroups, differentiated by some marker genes: ALDH1A1, KLF4, LEPR, CXCL12, C3, ACTA2 (αSMA), TAGLN, FAP and COL1A1 (26).