IFNG and neoplasm: Differentiation of stem cells and their resistance to NK cell mediated cytotoxicity correlated with significant increase in the expression of MHC class I, CD54, B7H1 surface expression in a number of healthy and tumor stem cell models, and it was blocked by the addition of the combination of anti-TNF-α and anti-IFN-γ antibodies, which restored NK cell cytotoxicity and blocked the increased expression of above-mentioned surface markers in addition to inhibition of cytokine and chemokine secretion ([39, 40].