CXCR1 and neoplasm: Given that several αvβ6-positive tumor cell lines were found to secrete IL-8 both in vitro and when grown as xenografts in vivo, we engineered A20-28z CAR T-cells to co-express the IL-8-specific chemokine receptors, CXCR1, or CXCR2 (Figure 2B).