CD8A and neoplasm: The reason we focus solely on T-cells lies in that CD8 + T cells are the most prominent anti-tumour cells and cause the direct destruction of target cells (González et al. 2018; Whiteside 2022), and tumour infiltrating cells, which are immune cells that have migrated from the blood stream into tumour tissues with the purpose of tumour elimination, consist mostly of CD3 + T cells and a smaller proportion of B and NK cells, whose functions are less clear (Liu et al. 2023).