To examine whether circFGFR1 promotes NSCLC cell proliferation, migration, and invasion via the miR-381-3p/CXCR4 axis, we established CXCR4-knockout NCI-H358 and NCI-H1299 cells (NCI-H358-CKO and NCI-H1299-CKO cells) through CRISPR/Cas9 (Additional file 4: Figure S7a). The gene discussed is CXCR4; the disease is non-small cell lung carcinoma.