Since CAR T cells elaborate high levels of pro-inflammatory cytokines when exposed to tumor cells, as shown in Fig. 5, we endeavored to determine whether the down-modulation of CD19, CD22 or CD20 on Raji cells following co-incubation with CART cells is a direct effect of CAR T-tumor cell contact, or is due to soluble factors released to the medium by CAR T cells. Here, CD22 is linked to neoplasm.