The product is a recombinant, nonglycosylated human interleukin-1 receptor antagonist (IL-1Ra). The difference between the product and the native human IL-1Ra is that the product has an extra methionine residue at the amino terminus. It is manufactured by using the E. coli expression system. The product is composed of 153 amino acid residues. Kineret https://www.creativebiomart.net/therapeutic-proteins/p/110/recombinant-nonglycosylated-human-interleukin-1-receptor-antagonist-il-1ra/