MR1 and neoplasm: It detects phosphoantigens resulting from mevalonate pathway dysregulation in tumor cells, while Vδ1+ (delta 1 subset of gamma delta T cells) subsets dominate mucosal sites and target non-classical MHC molecules, such as CD1 (family of glycoproteins) and MR1 (MHC class I-related protein 1) [16,27].