GRO beta is a member of the CXC, or chemokine class. It contains the ELR domain immediately preceding the first cysteine residue near the amino terminus. Other chemokines in this group include IL8, GRO alpha/beta/gamma, mouse KC, ENA78, GCP2, PBP/CTAPIII/beta TG/NAP2. These chemokines act primarily on neutrophils as chemoattractants and activators, including neutrophil degradation with release of myloperoxidase and other enzymes. GRO beta was originally identified as a heparin-binding protein