STUB1 and lung cancer: CHIP assays using KLF4 antibody showed enrichment of miR-1915 promoter in A549 and H1975 cells, whereas negative control (IgG and Ab- groups) did not (Fig. 7H), demonstrating that KLF4 directly bound to the miR-1915 promoter in lung cancer cells and transcriptionally regulated miR-1915 expression.