TP53 and cancer: In terms of a previous study, it is the direct mutagenic action on DNA the means by which smoking causes lung cancer and the TP53 gene is one of the most frequent targets of tobacco smoking‐related DNA mutations.19 The findings of our study showed that smoking was significantly associated with high frequency of TP53 mutations, consistent with several studies in which TP53 mutations more frequently occurred in patients with smoking‐associated cancer (26%‐71%) compared with patients who never smoked (8%‐47%).20, 21, 22