The CTSK (cathepsin K) antibody is a crucial tool for studying the role of cathepsin K, a lysosomal cysteine protease primarily expressed in osteoclasts, where it degrades collagen and other extracellular matrix components during bone resorption. CTSK is implicated in bone remodeling, osteoporosis, arthritis, and metastatic bone diseases due to its collagenolytic activity. Researchers use CTSK antibodies to detect and quantify CTSK expression in tissues or cells, facilitating investigations into osteoclast function, bone metabolism disorders, and pathological conditions like cancer metastasis. These antibodies are widely applied in techniques such as Western blotting, immunohistochemistry, and immunofluorescence. Additionally, CTSK inhibitors are being explored as therapeutic agents for bone-related diseases, making CTSK antibodies vital for evaluating drug efficacy and target engagement in preclinical studies. Their specificity and reliability also support diagnostic applications in differentiating bone disorders.