HLA-G and nonpapillary renal cell carcinoma: Furthermore, a loss of HLA-G mRNA and cell surface expression of ccRCC cells was observed during cell culture, which might be explained by the absence of TFs modulated by the hypoxic microenvironment, the lack of cytokines, such as IFN-γ, IFN-α and IL-10, or an increasing promotor methylation (96).