Next, we used single‐factor detection by enzyme‐linked immunosorbent assay (ELISA) assay, which showed that concentrations of cardiac troponin T (cTnT), creatine kinase isoenzymes MB (CK‐MB), and L‐lactate dehydrogenase (LDH) were elevated in radiotherapy patients for thoracic tumors, but significantly decreased in non‐radiotherapy patients, suggesting the damaged role of radiation such as X‐ray in cardiac functions and structure. This evidence concerns the gene TNNT2 and neoplasm of thorax.