However, there is some caution since vitamin E and NAC in a combination study showed increased tumor cell proliferation by reducing reactive oxygen species and reducing p53 expression (which increases tumor growth) in mouse and human lung tumor cells [89], whereas NAC and a major tea polyphenol epigallocatechin-3-gallate (EGCG) form an adduct which may enhance EGCG cell killing of cancer cells [90]. This evidence concerns the gene TP53 and neoplasm.