Sialic acids (Sias) are typically found as terminal monosaccharides attached to cell surface
glycoconjugates. They play many important roles in many physiological and pathological
processes, including microbe binding that leads to infections, regulation of the immune
response, the progression and spread of human malignancies and in certain aspects of
human evolution. This review will provide some examples of these diverse roles of Sias and
briefly address immunohistochemical approaches to their detection.