SHH and Alzheimer disease: We induced AD in mice in which Gli2-mediated transcription is constitutively inhibited in T cells only: lck-Gli2ΔC2 transgenic mice express a truncated form of Gli2 that can function only as a transcriptional repressor, and by binding consensus GBSs inhibits normal Hh-mediated transcription, rendering T cells refractory to upregulation of Ptch1 on Shh treatment (18).