Accumulating experimental and clinical studies have shown that activation of CAPN2 plays a critical role in tumorigenesis and progression in various tumors, including ovarian cancer (12), colorectal cancer (13), gastric cancer (14), hepatocellular carcinoma (15), non-small cell lung cancer (16), and prostate cancer (17). The gene discussed is CAPN2; the disease is non-small cell lung carcinoma.