CD19 and neoplasm: Based on the role of the CD40 pathway in improving anti-tumor response, some researchers combined CD28 with CD40L in CD19 CAR-T, which up-regulate the proliferation of T cells, the expression of CD80 and CD40 of dendritic cells after co-culture with CD40-positive tumor cells, increase the recruitment of endogenous effector T cells by DC, and enhance the immunogenicity of CD40-expressing tumor cells.