Calibrator 3 is a lyophilized blend of 10 recombinant human proteins: G-CSF, IFN-α2a, IL-1α, IL‑7, IL-12/IL-23p40, IL-15, IL‑16, IL-18, TNF-β, and TPO. It was developed for use as an assay calibrator for MSD U-PLEX human and non-human primate assays that measure any of the included proteins. The utility of this product has not been evaluated in other applications. Individual analyte concentrations are provided in the lot-specific certificates of analysis. Calibrator 3 includes G-CSF, IFN-α2a, IL-1α, IL‑7, IL-15, IL‑16, IL-18, and TNF-β expressed in E. coli, IL-12/IL-23p40 expressed in an insect cell line, and TPO expressed in a mouse cell line. The instructions on using Calibrator 3 in U-PLEX assays are provided in U-PLEX Biomarker Group 1 Human Product Inserts and U-PLEX Biomarker Group 1 NHP Product Inserts.