Reg3B (regenerating islet-derived protein III beta; also PAP-I and HIP) is a secreted 17 kDa member of the Reg gene family, C-type lectin gene superfamily. It is found in pancreatic acinar cells, intestinal enterocytes, and developing spinal motoneurons. Reg3B may play a role in intestinal epithelial cell renewal. Mouse Reg3B contains one C-type lectin domain (aa 38 - 173). Mature mouse Reg3B is 59%, 71% and 51% aa identical to the products of three other Reg3 named genes termed Reg III alpha, gamma and delta, respectively. Mature mouse Reg3B is also 91% and 67% aa identical to rat and human Reg3B, respectively.