CD163 and neoplasm: Furthermore, a recent study that examined a subset of M1 (human leukocyte antigen DR (HLA-DR) and inducible nitric oxide synthase (iNOS)) and M2 (CD163 and VEGF-A) markers found that a high M1/M2 ratio was associated with improved survival, when present intra-tumourally, but not in the tumour stroma [48].