DCN and Penile Fibromatosis: Bone proteoglycan II precursor (PGS2, decorin), an inhibitor of TGF‐β1 with a role in fibroblast growth and collagen synthesis, was upregulated only in Peyronie's disease (Dupuytren disease, 0.5 ± 0.1 [n = 6]; Peyronie's disease, 2.5 ± 0.3 [n = 5]).35