Of note, it was recently reported that TGF-β1/Snail1 enhances the activation of both pulmonary fibroblasts and breast cancer TAFs by cooperating with two protein methyltransferases (PRMT1 and PRMT4) to promote arginine methylation in histones, which drive the expression of fibronectin and other pro-fibrotic genes [65], thereby supporting that histone methylation is involved in fibroblast activation and fibrosis [66]. Here, SNAI1 is linked to breast cancer.