SIRPA and neoplasm: Binding of the tyrosine-based inhibitory motif (ITIM)-containing inhibitory receptors signal regulatory protein-α (SIRPA)3 or sialic-acid-binding Ig-like lectin 10 (SIGLEC10)7 to their respective ligands CD47 and CD24 on tumour cells prevents activating receptors such as dectin-11, dectin-221 and the calreticulin receptor LRP1, which bind to glycoproteins on tumoural cells2,18, from initiating macrophage activation4,5,7.