Thus, we employed mass cytometry (CyTOF) to characterize the metabolic profiles and phenotypic traits of IL-7 secreting CD19 CAR T-cells with CD28 co-stimulatory domain at the single-cell level and examine the impact of IL-7 addition to CAR construct on anti-tumor response of CAR-T cells in vitro and in vivo. Here, IL7 is linked to neoplasm.