TNBS-produced colorectal inflammation does not differ between genotypes. Colorectal myeloperoxidase (MPO) activity did not differ between C57BL/6 and GFRα3 KO mice either before or after intracolonic saline or TNBS treatment. TNBS produced a similar significant increase in MPO in both genotypes on day 2 after treatment [treatment, F(2,15) = 33.79, P < 0.001; genotype, F(2,15) < 0.01, P = 0.981]. Data are presented as means ± SE (n = 3–6).