KLF9 is a target gene of miR-142-3p, and knockdown of KLF9 suppresses cell proliferation. (a) Schematic representation of wild type and mutant psi-CHECK2-KLF90-3ʹUTR miRNA expression vectors used in luciferase reporter assays. (b) Relative luciferase activities in 293T cells corresponding to the binding site, *** P < 0.001. (c-e) qRT-PCR, Western blot and IF analysis of the expression of KLF9 in CRL-7566 cells treated with KLF9-siRNA. (f) CCK-8 assay to evaluate the effect of KLF9-siRNA on CRL-7566 cell proliferation, ** P < 0.01. (g, h) EdU assay to assess the proliferation of CRL-7566 cells treated with KLF9-siRNA, *** P < 0.001. (i) Flow cytometry to measure the contribution of KLF9-siRNA to the cell cycle, *** P < 0.001.