COA6 regulates the proliferation of LUAD cells (A549 and H1975). (A) Histogram showing the known down of COA6 mRNA by siRNA (mean ± SD, n = 3); (B,C) Western blot showed that the decreased protein level of COA6 and COX2 by the knockdown of COA6 (mean ± SD, n = 3); (D) Immunofluorescence staining showing the inhibition of the COA6 protein expression, Magnification: 400×; (E) MTT showing the inhibited proliferation of cells by the knockdown of COA6, the optical density (OD) values of two groups were compared at the 96th hour (mean ± SD, n = 3); (F,G) Colony formation assay showing the reduced number of colonies by the knockdown of COA6 (mean ± SD, n = 3). t−test of independent samples was used in comparing the means of two groups, * p < 0.05, ** p < 0.01, and *** p < 0.001.