Sialic acids are a family of nine-carbon sugars that play a crucial role in cellular interactions and signaling. They are commonly found on the surface of cells, where they help protect cells from being recognized by the immune system. Sialic acids are important for various biological processes, including cell communication and pathogen recognition. These sugars are often attached to glycoproteins and glycolipids, which are molecules made of carbohydrates and proteins or lipids. In humans, the most prevalent sialic acid is N-acetylneuraminic acid, which is involved in numerous physiological functions, including inflammation and infection response.