GPBAR1 and Leber congenital amaurosis: Analysis of the phosphorylation level of ERK1/2 kinase (Fig. 5b,c) and the use of MEK inhibitor (Fig. 5d) revealed that LCA and 3-oxoLCA induce expression of HDP cathelicidin in bronchial epithelium through the activation of TGR5-ERK1/2 pathway.