Abstract
Fast varying 3-O-sulfated groups in epithelial KIT+ progenitors provides a cellular mechanism to respond to FGFR2b-mediated signaling and expansion of fetal and adult progenitors. This is allowed by the synthesis of 3-O-sulfated heparan sulfate that up-regulate KIT and 3-O-sulfotransferase enzymes, augmenting 3-O-sulfated heparan sulfate.