However, utilization of methylated substrates, such as α-methyl-D-galactoside, α-methyl-D-glucoside and mono-methyl succinate, was only observed in OVCAR4 cells with high endogenous expression of NNMT. Thus, comparison of endogenous NNMT expression with the level of adaptation to glucose deprivation in parental cell lines supports the hypothesis that NNMT increases metabolic plasticity of ovarian cancer cells by allowing them to efficiently utilize alternative energy substrates, such as methylated carbohydrates. This evidence concerns the gene NNMT and ovarian carcinoma.