This term is obsolete
Consider
GO:0009505,GO:0016049
OBSOLETE. A group of proteins located within the cell walls of plants, both dicots and grasses, that play an essential role in loosening cell walls during cell growth. They are hydrophobic, non glycosylated proteins of about 30kDa. [ https://www.worldcat.org/search?q=bn%3A0198547684 ]
Synonyms: expansin
This is just here as a test because I lose it