Interestingly, in COPD patients only, there was an association between high basal cell proliferation and a high eosinophil count (r2 = 0.382, p = 0.032), a decrease in ciliated cell surface and a high eosinophil count (r2 = 0.594, p = 0.002) and an increase in MUC5b‐secreting cells and low neutrophil count (r2 = 0.539, p = 0.038) (Figure 1c,d). Here, MUC5B is linked to chronic obstructive pulmonary disease.