FOXO1 and non-small cell lung carcinoma: When miR-31-3p was overexpressed in A549 cells, the expression level of FOXO1 decreased, but after suppressing the miR-31-3p expression, the expression of FOXO1 increased (Figures 3(d) and 3(e)), suggesting that miR-31-3p can targeted-regulating the expression of FOXO1 in NSCLC.