CD4 and cancer: Furthermore, microRNA-25-3p, microRNA-155-5p, microRNA-215-5p, and microRNA-375 present in EVs derived from CD4 T cells have been demonstrated to influence CD8 T cell proliferation and activity, thereby enhancing their antitumor effect.[52] This may provide a foundation for new research directions, whereby scientists could utilize engineered T cells to block relevant cancer immune checkpoints, alter the function and phenotype of tumor cells, and inhibit cancer onset.