RRM2 and non-small cell lung carcinoma: In parallel, miR-20a-5p, another member of miR-20, acts as a tumor suppressor of NSCLC by regulating the ribonucleotide reductase regulatory subunit M2 (RRM2)-mediated PI3K (phosphatidylinositol 3-kinase)/Akt (serine/threonine kinase 1) axis [35].