In patients with severe asthma, MBD2 levels were positively correlated with MPO (r = 0.750, P < 0.001; Figure 4A) and Th17 (r = 0.454, P = 0.010; Figure 4B), but negatively correlated with FEV1/FVC (r = −0.429, P = 0.016; Figure 4C), FEV1%predicted (r = −0.371, P = 0.040; Figure 4D), Th2 (r = −0.565, P = 0.001; Figure 4E) and ECP (r = −0.418, P < 0.019; Figure 4F; Table 3). Here, MPO is linked to asthma.