However, compared to WT mice, Tgfβ-R expression was significantly reduced in M1R-deficient mice exposed to both PBS (1.0 ± 0.04 vs. 0.62 ± 0.03 fold respectively, p < 0.001) and AOM (2.6 ± 0.3 vs. 1.6 ± 0.3 fold respectively, p < 0.05; Fig. 2E), suggesting Chrm1 gene ablation reduces HSC activation by attenuating TGFβ-R expression. The gene discussed is CHRM1; the disease is infectious otitis media.