CD4 and neoplasm: Secondly, the designed CAR structure can release free Anti-MICB-scFv, which can bind to MICB on the surface of tumor cells: this will newly reactivate NK and other relevant immune cells in vivo; modulate the secretion of chemokines in the tumor microenvironment (TME); and recruit CD8+ T cells, CD4+ T cells, and NK cells to co-infiltrate tumor tissues.