MRC1 and neoplasm: Given the established importance of infiltrated macrophages in the suppression of UBC cell proliferation and stemness by SPOP, and considering the opposing roles of M1-like and M2-like macrophages in tumor growth 22, we assessed the mRNA levels of macrophage biomarkers, including the pan-marker (CD68), M1 marker (CD86 and iNOS), and M2 markers (CD163, CD206 and CCL22) in U937 cells co-cultured with UBC cells.