Nicotiana Benthamiana Callus Extract/sr-(Nicotiana Benthamiana Polypeptide-1 sh-Polypeptide-6 Tetrapeptide-123) is a single chain recombinant peptide, produced by Nicotiana benthamiana callus after transformation with either a transient expression system or transgenesis (stable insertion of a copy of the synthetic gene into its DNA), where the final product contains proteins from the callus of Nicotiana benthamiana grown in culture. The starting gene is synthesized by the fusion of the gene from sr-Nicotiana Benthamiana Polypeptide-1, sh-Polypeptide-6, and Tetrapeptide-123. The fusion peptide contains 194 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 standard amino acids.