We previously demonstrated that the subcutaneous injection of a recombinant protein consisting of the polycystic kidney disease (PKD) and Clostridium histolyticum collagenase collagen-binding domains (CBD) fused to basic fibroblast growth factor (bFGF; bFGF-PKD-CBD) had greater skin fibroblast growth-promoting effects in nude mice than native bFGF [27]. Here, FGF2 is linked to polycystic kidney disease.