TRIM is an inhibitor of nNOS and iNOS. It exhibits IC50 values of 28.2 μM, 27.0 μM, and 1.06 mM for the inhibition of nNOS (mouse), iNOS (rat), and eNOS (bovine), respectively.{5918} TRIM inhibits mouse nNOS with Ki values of 47.3 and 462 μM in the absence and presence of BH4, respectively, suggesting TRIM interferes with both arginine and tetrahydrobiopterin binding.{6635}