This process is RANKL-dependent and is of interest with regard to tumour osteolysis associated with Ewing's sarcoma as TAMs form a significant inflammatory component of rapidly growing malignant tumours (Bugelski et al, 1987; Walter et al, 1991; Mantovani et al, 1992; Van Ravenswaay et al, 1992). This evidence concerns the gene TNFSF11 and neoplasm.