A–F. Total protein and RNA from A549, H1792, and Calu-1 cells were isolated after treatment with 1 μM of ATRA for 96 h. The expression of Rig-G protein was analyzed by western blot (A and E). The expression of Rig-G mRNA in three NSCLC cell lines (B–D and F) was measured by real-time PCR. The results are expressed as the mean ± SEM, ***p < 0.001 G. Lung cancer cell lines A549, H1792, and Calu-1 were treated with 1 μm ATRA for 96 h, after which cell proliferation was measured by ELISA (BrdU labeling) analysis. The results are expressed as the mean ± SEM, **p < 0.01; ***p < 0.001; n.s., not significant. H. A549, H1792, and Calu-1 cells were treated with 1 μm ATRA and assessed for growth in soft agar by using the anchorage-independent colony formation assay. Scale bars = 500 μm. I. The maximum colony size of A549, H1792, and Calu-1 cells in a soft-agar assay was determined. The results are expressed as the mean ± SEM, ***p < 0.001; n.s., not significant.