Real-time quantitative PCR (RT-qPCR) was used to detect the expression levels of miR-31-3p and forkhead box 1 (FOXO1) in NSCLC tissues, serum, and cells to analyze the correlation between the expression levels of miR-31-3p and the clinicopathology of NSCLC. This evidence concerns the gene FOXO1 and non-small cell lung carcinoma.