In a genetically modified metastatic CRC mouse model, depletion of alpha smooth muscle actin (αSMA)+ CAFs resulted in an increase of forkhead box protein 3 (Foxp3)+ regulatory T cells (Tregs) and suppression of CD8+ T cells via BMP4/TGF-β1 paracrine signaling, ultimately promoting CRC invasiveness and lymph node metastasis [124]. Here, BMP4 is linked to colorectal carcinoma.