Recent laboratory studies indicated that the overexpression of angiotensin II type 2 receptor gene induced cell death in lung adenocarcinoma cells [45] and angiotensin-converting enzyme 2 attenuated the metastasis of non-small cell lung cancer through inhibition of epithelial-mesenchymal transition [46], which indirectly supported our results of subgroup analysis focusing on lung cancer. The gene discussed is ACE2; the disease is lung adenocarcinoma.