ACTA2 and breast cancer: On the other hand, co-cultures established under paracrine conditions—separated by a permeant membrane allowing the exchange of soluble factors—did not induce significant changes in the mRNA levels of CDH1, VIM, and MKI67 in the BC cells, genes associated with epithelial-to-mesenchymal transition (EMT) and proliferation (Supplementary Figures S1B–D), neither in the expression of genes associated with CAF biology, such as FN1, FSP1, ACTA2, FAP, CDH2, and VIM (Supplementary Figures S1E–J).