Next, we selected 12 known tumor suppressor genes implicated in cancer development, including GRHL3, NAV3, AXIN2, FOXP1, WISP3, SPDEF, RASSF1, PTPRG, IGFBP4, FHL1, FEZ1, and DUSP4, and using RT-qPCR, validated that their expression decreased in SIRT1-overexpressing tumor samples (Fig. 6K), thus further validating our RNA-seq results. The gene discussed is SIRT1; the disease is cancer.