Declaration of Competing Interest
Geun-Joong Kim, Hye-Ji Choi, Hanui Lee, Dae-Eun Cheong and Su-Kyoung Yoo declare that they have conflict of interest as the method for preparing recombinant FGF7 through circular permutation has been filed as patents (Korean Patent Application No. 10-2022-0051241, United States of America Patent Application No. 18/061,836). Dong-Eun Lee declare no competing interests.