Clinical observations and in vivo animal experiments show that local radiotherapy induces a selective rearrangement of tumor infiltrating lymphocytes by depleting radiosensitive immune cells such as CD8+ cytotoxic T cells and increasing the fraction of regulatory T cells and tumor infiltrating macrophages with an immune suppressive phenotype or by inhibiting CD8+ T cell responses in the tumor microenvironment through tumor infiltrating myeloid suppressor cells (Zhang et al. 2021; Shi et al. 2018). Here, CD8A is linked to neoplasm.