ENTPD2 and neoplasm: The failure of IR-treated cancer cells depleted from Atg5 to induce a protective immune response in vivo could be corrected by intratumoural injections of ARL67156 (ARL), an inhibitor of ecto-ATPases (apyrases) that artificially increases extracellular ATP concentrations.43 ARL injections enhanced the efficacy of IR therapy against autophagy-deficient CT26 cancers, hence significantly reducing tumour growth.