CD274 and bone metastasis: Age, sex, smoking status, PS score before receiving immunotherapy, PD-L1 expression, TNM and clinical stage, vascular invasion, pleural metastasis, extra-thoracic metastasis, brain metastasis, liver metastasis, bone metastasis, adrenal metastasis, received chemoimmunotherapy or not, received immunotherapy plus antiangiogenic therapy or not, neoadjuvant immunotherapy, and immunotherapy lines were chosen as the predictive variables.