Nicotiana Benthamiana sh-Polypeptide-45 is a single chain recombinant human peptide, produced by Nicotiana benthamiana after transformation with either a transient expression system or transgenesis (stable insertion of a copy of a human gene into its DNA). The starting gene is synthesized to be identical to the human gene which codes for Granulocyte Macrophage Colony Stimulating Factor. It contains a maximum of 144 amino acids, which may contain disulfide bonds and/or glycosylation. The protein consists of the proper sequence of the 20 standard amino acids.