YY1 promotes the secretion of exosomes to promote prostate cancer progression, and YY1 upregulates polycom, also named pentraxin domain containing 1 (SVEP1), in cancer-associated fibroblasts (CAFs), which secrete miR-146a-5p and increase urothelial bladder cancer resistance [7,40,41,42]. Here, YY1 is linked to bladder transitional cell carcinoma.