NQO1 and infectious otitis media: Expression of Nqo1 was also similar in PBS-treated mice; however, compared to AOM-treated WT mice, Nqo1 expression increased significantly in AOM-treated M1R-deficient mice (2.42 ± 0.31 vs. 10.29 ± 1.74 fold respectively, p < 0.001; Fig. 5F).