CD8A and neoplasm: CD4+ T cells have an important regulatory effect, and CD8+ T cell stem cell-like subgroups have the potential to self-proliferate and differentiate toward effector cells, which can produce durable anti-tumor immune response and specifically kill tumor cells (Borst et al., 2018; Farhood et al., 2019; He et al., 2019; Brightman et al., 2020).