PROCR and infection: Regardless, our observations that small molecules and chemical modifications on proteins are γδ T cell targets suggest a new category of antigen specificity in addition to cell surface molecules such as the non-classical MHC class I molecules T10 and T22, MHC class I-related chain A/B (MICA/B), and endothelial protein C receptor (EPCR) (Willcox et al., 2012) that can activate γδ T cells in infection and inflammation.