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). Here, MKI67 is linked to breast cancer.