PDE4B and lung cancer: Six genes showed particularly stronger expression pattern in lung cancer tissues, as compared to normal lungs (Figs. 9, 10, 11, 12, 13 and 14), which demonstrated that these six genes (GABBR1, PDE4B, PDE4C, ADCY6, ADCY1 and GIPR) had more likelihood of being direct targets of miR-542-5p in lung cancers.