GPR17 is a G protein-coupled receptor that has been identified as a dualistic receptor recognizing signals from two unrelated chemical families: nucleotides and cysteinyl leukotrienes (CysLTs).1 The deorphanization of GPR17 supports the suggested crosstalk between nucleotides and CysLTs during inflammation and injury. mRNA transcripts encoding this transmembrane receptor are most strongly expressed in the brain, kidney, and heart. Upon ischemic injury, GPR17 is upregulated in these tissues and its inhibition has been shown to decrease ischemic damage.This finding suggests GPR17 as a pharmacological target of ischemic injury.1 Caymans peptide affinity-purified polyclonal antibody recognizes the C-terminal region of human GPR17. This protein exists in two isoforms, differing by 28 amino acids at the receptor N-terminus. The longer form of the protein consists of 367 amino acids with a calculated molecular weight of 41 kDa. The human and rat proteins share 89% amino acid identity.1 Post-translational modifications may explain the observed SDS-PAGE gel-migration to 57 kDa on immunoblot.