To gain mechanistic insight into the functional state of Reg-1 KO B7-H3-CAR, Ctrl KO B7-H3-CAR, or Reg-1 KO SP6-CAR T cells and their effects on endogenous immune cells, we euthanized F331 tumor-bearing mice on day 7 or day 21 or M119 tumor-bearing mice on day 7 or day 28 post CAR T cell infusion. The gene discussed is SP6; the disease is neoplasm.