Decorin was initially defined as structural components modulating the synthesis, organization, and assembly of collagen fibrils [1,2], but with time has evolved as a versatile proteoglycan, involved in various biological processes such as cell proliferation, differentiation [3], matrix adhesion [4], autophagy [5], inflammation and immunity [6], angiogenesis [7], tumorigenesis [8], osteoarthritis and osteoporosis [9–11], and fibrosis [12]. Here, DCN is linked to osteoporosis.