In fact, variants of DbpA, an adhesin that binds to the proteoglycan decorin and the glycosaminoglycan (GAG) dermatan sulfate, exhibit differences in GAG- and decorin-binding in vitro, and isogenic B. burgdorferi strains that differed only in the coding sequence of dbpA display differences in tissue tropism upon infection of laboratory mice [21–24]. This evidence concerns the gene DCN and infection.