CD4 and cancer: The TME contains a plethora of immune cells, such as monocytes, macrophages, natural killer cells (NKs), dendritic cells (DCs), lymphocyte B cells, and lymphocyte T cells (CD4+ and CD8+) that play key role in the antigen-presentation process and cancer immune cycle that can lead to tumor progression; therefore, targeting the TME and its components is considered a major mechanism for effective cancer vaccines [5,9,10,11].