L-NIL inhibited mouse inducible nitric oxide synthase with an IC₅₀ of 3.3 µM compared to an IC₅₀ of 92 µM obtained for rat brain constitutive NOS. The lysine-derived inhibitor may be useful as a selective and potent inhibitor of inducible NOS for determining the role of this enzyme in disease models (e.g. chronic inflammation and autoimmune diseases). Bryk et al. studied the suicidal disactivation of neuronal NOS by L-NIL.