Owing to the lack of significant difference in the smoking status and the smoking index between patients with TP53-mutated lung cancer located in segments 9 and 10 and that located in segments 1 to 8, we concluded that even a comparable amount of smoking may exert a strong effect on cancer initiation and progression in segments 9 and 10 in the dorsal inferior lobe. This evidence concerns the gene TP53 and lung cancer.