Recombinant human CD38 encompassing amino acids 43 to 300 (end). This construct contains a C-terminal Avi-Tag™ followed by a His-tag (6xHis). The recombinant protein was enzymatically biotinylated using the Avi-Tag™ and affinity purified. HiP™ indicates a high purity protein (≥90% pure) and less than 10% aggregation as measured by gel filtration.