In 2020, Professor Lu You reported that HFRT can induce stronger local and systemic anti-tumour immune effects than conventional fractionated radiation therapy (CFRT) by inhibiting the VEGF/VEGFR signalling pathway, reducing MDSCs recruitment to the tumour microenvironment, mediating lower PD-L1 expression, decreasing tumour cells for immune escape through the PD-L1/PD-1 axis, increasing CD8+ T cell levels around tumour tissues and in peripheral blood and maintaining their tumour cell killing activity (44). Here, KDR is linked to neoplasm.