The results of the analysis revealed that Sirt1 expression was significantly associated with the Ki67 index (P=0.002), HIF1 expression (P=0.05) (Fig. 2), tumour-node-metastasis (TNM) stage (P=0.002) (Fig. 3), particularly in lymph node invasion (Fig. 4) and metastasis (Fig. 5), and with a higher number of pulmonary vein invasion (P=0.039) (Fig. 6) and lymphatic duct invasion (P=0.004) (Fig. 7). The gene discussed is MKI67; the disease is neoplasm.