interferons

https://doi.org/10.1351/goldbook.I03095
A class of glycoproteins (with sugar groups attached at specific locations) important in immune function. They are able to inhibit the multiplication of viruses in cells.
Source:
PAC, 1992, 64, 143. 'Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992)' on page 158 (https://doi.org/10.1351/pac199264010143)