Compounds, compositions, and methods for modulating in vitro and in vivo processes mediated by selectin binding. For example, heterobifunctional compounds that inhibit both E-selectins and P-selectins are described, wherein the selectin modulators that modulate (e.g., inhibit or enhance) a selectin-mediated function comprise particular glycomimetics linked to a member of a class of compounds termed BASAs (Benzyl Amino Sulfonic Acids). The compounds are of formula (Ia) wherein the substituents are as defined in the claims.
