Bai L, et al. - In lung cancer patients receiving radiotherapy, a case-control study with frequency matching was conducted to examine connections among serum T-cell subsets, CRP, levels and radiation pneumonitis (RP). The case group included 36 lung cancer patients who had developed grade ≥ 2 RP after thoracic radiotherapy. There were 36 patients with lung cancer without RP in the control group. Steroid treatment was given to patients in the case group for 1 month after RP diagnosis and followed up for 3 months. At three time points (onset of RP and 1 and 3 months after diagnosis), T-cell subsets, CRP, and pulmonary function were identified. Findings suggested that T-cell subsets and CRP can become effective immunological biomarkers to predict RP damage and assess the efficacy of steroid therapy treatment.