CD8A and neoplasm: For example, CD8, CD4, CD19+, FoxP3, CD56+, PD-1, PD-L1, CD3, CD68, CD11c, IDO-1, etc., can be used for immune cell subpopulation identification to illustrate the effect of FLASH radiotherapy on tumor immune activation, and the alteration and evolution of immune cell subpopulations such as locally infiltrating lymphocytes, dendritic cells, and macrophages.