Human NRG-1 (Neuregulin 1) protein is frequently used in the maintenance of human pluripotent stem cells. In addition to its widespread use in stem cell culture media, NRG-1 (also known as Heregulin-β1 , HRG-1) has essential roles in vivo including in nervous system, cardiac, and mammary gland development; cancer biology and neurological disorders. 7.5 kDa highly pure, bioactive domain of human NRG-1, comprised of the β isoform of the EGF-like domain of NRG-1 (HRG1-B1). This NRG-1 protein monomer is animal-free (AF) and carrier-protein free (CF).