The two enantiomers of VC known as the L- and D-forms of ascorbic acid (D-VC and L-VC) in combination with arsenic trioxide have a similar potent cytotoxic oxidizing effect on cancer cells, but the use of D-VC has been shown to be more effective in suppressing KRAS mutant tumor growth [4,17]. This evidence concerns the gene KRAS and cancer.