Both the percentage of β2-AR-positive fibrocytes (Fig. 3e) and the β2-AR MFI ratio (Fig. 3f) were lower on the surface of circulating fibrocytes of patients with severe asthma compared to healthy subjects, although whole cell β2-AR expression was not significantly different between the two groups (Fig. 3g and h). Here, ADRB2 is linked to asthma.