Considering that only FGFR1 is suppressed during COPD (Fig. 6B and Additional file 1: Figure S5) and FGFR1 is the predominant FGFR expressed in pulmonary endothelial cells (Fig. 6C), we focused on the FGFR1 signaling, and found that FGF10 activated the FGFR1 and its downstream signaling ERK and AKT, which could be inhibited by AZD4547 (Fig. 6D and E). Here, AKT1 is linked to chronic obstructive pulmonary disease.