MRC1 and melanoma: Since monocytes and macrophages play a key role in innate immune surveillance and in tumor biology, we examined the polarity effects of exosomes derived from melanoma cells exposed to either IH or normoxia on naïve THP1 monocytes and macrophages using specific genes for M1 markers (namely CCR7, CXCL10 and IL6), and for M2 markers (CD206, CD163, and IL10).