The results demonstrate that ectopic lnc-GAN1 expression upregulates PTEN mRNA and downregulates mir-26a-5p in A549 cells (Fig. 6d upper-penal), while lnc-GAN1 knockdown exerted the opposite effects in H1299 cells (Fig. 6d lower-panel), suggesting that the tumor-suppressor role of lnc-GAN1 is mediated by PTEN via this lncRNAs’ sponging and inhibiting miR-26a-5p. The gene discussed is PTEN; the disease is neoplasm.