Cathepsin K (CTSK), tartrate-resistant acid phosphatase (TRAP), dendritic cell-specific transmembrane protein (DC-STAMP), osteoclast-associated receptor (OSCAR), and others are involved in cell differentiation, and their increased expression can result in the differentiation of osteoclasts into mature osteoclasts, potentially exacerbating osteoporosis [8,9,10,11,12]. Here, ACP5 is linked to osteoporosis.