CD4 and neoplasm: For example, help from CD4+ T cells is critical for the activation and persistence of CD8+ T cells,[40] such as the ability to enhance tumor eradication by CD8+ T cells.[41] As a corollary of the different expansion rates of CD4 and CD8 cells in vitro, a skewed CD4:CD8 ratio after expansion compared to pre‐manufacturing cells was observed (Figure S9a, Supporting Information).