Of the three upregulated genes, CDK8 and PTGS2 have been reported to be oncogenic gene [31, 32], which cannot mediate the tumor-suppressor role; PTEN is one of the most important tumor suppressor genes in cancers, and meets both requirements: a direct target of miR-26a-5p and a possible indirect downstream gene of the tumor-suppressive lnc-GAN1. This evidence concerns the gene PTGS2 and cancer.