Interestingly, high dietary VD/VD-deficient doses did not affect the number of lung adenocarcinomas in either Smad3+/− or wild type mice (Fig. 1c, Supplementary Table S1), and we did not observe a noticeable increase in total tumor burden in the lung at the time the data was collected, suggesting VD levels on tumorigenesis appear to be restricted to the liver. Here, SMAD3 is linked to lung adenocarcinoma.