The administration of Polyphenon E and Caffeine not only reduced the incidence and multiplicity of lung adenocarcinoma in female A/J mice induced by NNK, but also inhibited cell proliferation, enhanced apoptosis, and lowered levels of c-Jun and ERK1/2 phosphorylation in adenocarcinomas and adenomas, suggesting that tea polyphenols (and perhaps caffeine) inhibit NNK-induced lung tumorigenesis [46]. This evidence concerns the gene MAPK3 and lung adenocarcinoma.