At the same time, the level of PDCD4 in some NSCLC cell lines, e.g., H661 cells and U1810 cells, was remarkably higher than that in normal lung cells (Fig. 5A–C), which raised questions on the role between SND1 and PDCD4 in NSCLC cells with high PDCD4 levels. This evidence concerns the gene PDCD4 and non-small cell lung carcinoma.