SOX9 and cystic fibrosis: While ASPN is known to regulate fibrosis and calcification in different cell types and organs (32–34), and SOX9 is known to regulate MF transition and calcification in different cell types (35–37), thus far, the role of ASPN in CF-to-MF transition and the roles of both SOX9 and ASPN in CF-to-OF transition remain unknown.