Although CD8+ CAR-T cells are considered the leading player of tumor killing, several studies have shown that the presence of both CD4+ and CD8+ CAR-T cells with a defined ratio within the final product can result in a better and more durable anti-tumor function (Sommermeyer et al., 2016; Turtle et al., 2016; Boulch et al., 2023; Lee et al., 2023; Melenhorst et al., 2022). This evidence concerns the gene CD8A and neoplasm.