In non-small cell lung cancer, tumor suppressor miR-340 directly binds to the 3′UTR of Pum1 and Pum2 mRNA to inhibit their expression, thus reducing PUM1 and PUM2 that are required for the miR-221/222 interaction with the p27 3′UTR64. Here, PUM2 is linked to non-small cell lung carcinoma.