FGFR1 and renal fibrosis: In conclusion, this study identifies the endothelial FGFR1/YAP1 axis as one of the important pro-fibrotic drivers in renal fibrosis progression and proposes an innovative therapeutic concept: indirectly modulating the "undruggable" transcriptional co-activator YAP1 by targeting its upstream, pharmacologically tractable receptor FGFR1.