RAW264.7 cells rapidly differentiate into osteoclasts in response to RANKL alone109; notably, M-CSF even suppresses osteoclast formation and activity in these cells when combined with RANKL.110 BSP has not been studied in human systems such as THP-1 (human leukaemia monocytic cell line) cells111 or primary human osteoclasts,112 limiting translational relevance. This evidence concerns the gene TNFSF11 and leukemia.