RIGI and neoplasm: The described effects of ADAR loss in overcoming immunotherapy and radiotherapy have been linked to its ability to reduce the levels of innate ligand dsRNA and subsequent inhibition of the dsRNA sensors PKR, and MDA5/RIG-I, involved in growth inhibition and tumour inflammation, respectively.4,5,46 ISGylation of PKR has been reported to activate its activity, and we could also see ISGylation and activation of PKR in the USP18 KO cells treated with IFN.