PTPRC and neoplasm: To further validate and quantify SCAM self-maintenance and rule out the possibility that Nod Scid-specific macrophages are phagocytosing Uty+ tumor epithelial cells, we took advantage of the ability to discriminate between our tumor mouse (donor), and NOD SCID mouse (host or recipient) strains through the expression of different Cd45 allelic variants (Fig. 8c and Supplementary Fig. 7a, b).