Figure 4. FiRE activation by X-Gal staining differs in mucosal and cutaneous wounds in organ culture. In organ-cultured mucosal wounds, no activation of FiRE was detected at either 24 hrs (A) or 72 hrs (C). In organ-cultured cutaneous wounds, FiRE activation was clearly detectable at both 24 hrs (B) and 72 hrs (D). (E) The addition of EGF to organ culture of mucosal wounds activated FiRE. (F) Mucosal wound without the addition of EGF. * = wound site.