IL2 and cancer: In another example, the Hubbell group developed strategies for the delivery and release of both immune checkpoint inhibitor antibodies (αCTLA4 + αPD-L1) and interleukin-2 (IL-2) using collagen-binding domains (CBDs) derived from the von Willebrand factor (vWF) A3 domain to immobilize drugs on collagen in the tumor stroma for cancer immunotherapy (Ishihara et al., 2019).