IC50 values for the urea-based inhibitors N-cyclohexyl-N′-ethylurea (CEU), N,N′-dicyclohexylurea (DCU), N-cyclohexyl-N′-dodecylurea (CDU), N-adamantyl-N′-cyclohexylurea (ACU), and 12-(3-adamantane-1-yl-ureido)-dodecanoic acid (AUDA). Recombinant chicken soluble epoxide hydrolase (sEH) was partially purified as described. Assay conditions are described in the Materials and Methods section. Error bars represent the standard deviations.