MJN228 is a selective ligand for the lipid-binding protein nucleobindin 1 (NUCB1), blocking binding of the probe arachidonoyl ethanolamide-diazirine with an IC50 value of 3.3 μM. It prevents probe binding to NUCB1 in Neuro2a cells at concentrations as low as 10 μM. MJN228 has been used to elucidate the role of NUCB1 in lipid metabolic pathways in cells.