Consistently, knock-down of circRNA CDR1as inhibited cell proliferation and viability, but increased cell apoptosis ratio in DDP-resistant NSCLC cells treated with high-dose DDP, which were all reversed by downregulating miR-641 and upregulating HOXA9, indicating that circRNA CDR1as ablation increased DDP chemosensitivity in NSCLC cells by downregulating HOXA9 through upregulating miR-641. This evidence concerns the gene HOXA9 and non-small cell lung carcinoma.