TP53 and lung cancer: This finding might be explained, in part, by previous studies using the lung cancer cell lines H1299 (p53−/−) and A549 (p53+/+), showing that nicotine induces more proliferation in lung cancer cells lacking p53 and that nicotine-dependent induction of survival signaling in lung cancer cells was dependent on p53, while curcumin completely blocked the over-expression of these survival pathways via p53-independent mechanisms [62].