Reclustering of the COL1A1-positive CAFs and removal of RGS5-positive pericytes resulted in four CAF subpopulations, of which the two major clusters (cluster 1 and 2) expressed iCAF and myCAF gene signatures, respectively (Fig. 4Q), confirming the presence of iCAFs and myCAFs in human breast cancer. Here, COL1A1 is linked to breast cancer.