TNFSF11 and neoplasm: In early skeletal metastases where a relatively high macrophage: tumour cell ratio and large number of osteoclasts are typically found (Galasko, 1976; Bugelski et al, 1985), RANKL-dependent and RANKL-independent mechanism of pathological bone resorption are likely to play a role in the establishment of a metastatic malignant melanoma in bone.