HLA-G and cancer: Conversely, increased percentages of circulating and tissue-infiltrating HLA-G+ immune cells (e.g., T and NK cells, monocytes, DCs, mast cells) can be observed in different pathological situations such as infections, cancers, transplants and autoimmune disorders suggesting a potential role for these cells in the pathogenesis of diseases in which immune system is strictly implicated (1, 2, 24, 36–38).