CD4 and neoplasm: Recently, Liu's group showed that both water‐soluble and solubilized water‐insoluble components can be encapsulated into cancer vaccines, owing to the technology they developed.[20, 37] Whole tumor antigen vaccines offer a relatively simple approach to circumvent some of these limitations by including a broad array of TSAs that contain epitopes for both CD8+ cytotoxic T cells (CTLs) and CD4+ T helper cells.