TKT and neoplasm: Given the selective depletion of GFAP+ enteric glial cells achieved with this regimen, we assessed overall tumor burden in ganciclovir-treated Gfap-tk and wild-type mice nine weeks after AOM/DSS induction and discovered that the tumor burden of Gfap-tk mice was reduced by approximately 90% (Figure 1A), imputing a critical role in tumor development to the enteric glia.