NR1I2 and epilepsy: Weaker activation was also achieved with two other planar ligands, carbamazepine (an anti-epilepsy medication) and n-butyl p-aminobenzoate (a compound that also activates African clawed frog PXRs [7,12,49], Western clawed frog PXR (this report), as well as several other PXRs [12]).