PTEN and non-small cell lung carcinoma: To investigate the effect of miR-4262 on NSCLC chemoresistance, A549/PTX, H1299/PTX and parental cells were transfected with pcDNA3.1, miR-4262 mimics, miR-4262 inhibitor, pcDNA3.1-PTEN and pcDNA3.1-PTEN + miR-4262 mimics.