RANKL (Receptor Activator of Nuclear Factor κB Ligand) and RANK (RANKL's receptor) are key members of the tumor necrosis factor (TNF) superfamily and receptor family, playing crucial roles in regulating bone metabolism and immune function. The binding of RANKL to RANK activates signaling pathways including NF-κB and JNK, thereby promoting the maturation and activation of osteoclasts, which play a critical role in bone resorption and remodeling processes. RANKL is primarily expressed by osteoblasts and lymphocytes, while RANK is mainly expressed on osteoclasts and their precursors. This interaction is essential for maintaining bone health, and imbalance in its expression is associated with various diseases such as osteoporosis, malignant tumor bone metastasis, and autoimmune diseases. Therefore, the RANKL/RANK system has become a potential target for treating these diseases.