HP and infection: For example, in C. trachomatis infection of epithelial cells, only HP oligosaccharides longer than dodecasaccharides and containing 6-O-sulfates inhibited infection.62 In hepatitis C virus infection of hepatoma cells, only HP oligosaccharides longer than decasaccharides and containing N- and 6-O-sulfate groups inhibited infection.63 The differences in size and sulfation requirements for inhibition illustrate the complex role of heparan compounds in modulating microbial pathogenesis.