CD4 and neoplasm: Spatially, more CD4<sup>+</sup> T cells infiltrate the tumor invasive margin and are located around CD31<sup>+</sup> endothelial cells after anti-PD-1 immunotherapy.<h4>Conclusions</h4>PD-1 inhibitors improve radiosensitivity through vasculature and immune reprogramming, and vessel normalization may be a biomarker for distinguishing patients who will benefit from radiotherapy after induction immunotherapy.