KLF5 and non-small cell lung carcinoma: However, KLF5 knockdown effectively overturned the cytotoxic effects of DDP on A549 (Fig. 2b) and H1299 (Fig. 2e) cells under a hypoxic condition versus si-NC group, indicating that KLF5 knockdown dramatically abolished hypoxia-induced DDP resistance in NSCLC cells.