SIRPA and osteosarcoma: 41 Shrestha et al. (2025) reported that combined inhibition of STAT3 and CD47 effectively suppressed lung metastasis in osteosarcoma, highlighting the therapeutic relevance of targeting this pathway 42. In clinical studies, the SIRPα receptor is expressed on macrophages and is an inhibitory immune receptor. After binding to the CD47 protein, it sends a 'do not eat me' signal. Given that CD47 is often overexpressed in cancer cells to avoid clearance by macrophages, treatments targeting CD47/SIRPα have been actively investigated 43, 44.