PTCH1 and posterior cortical atrophy: An in vivo study in the LADY PCa mouse model by Gipp and colleagues has shown that the expression of Hh signaling components, Shh, Ptch1 and Gli1 are not increased during PCa development [52], whereas another study by Bragina et al. using a TRAMP PCa mouse model did show an age-dependent increase in Hh activity associated with tumor development [53].