GLI2 and Alzheimer disease: To test if elevated Hh pathway activation in T cells can protect against AD, we induced AD in mice in which Gli2-mediated transcription is constitutively activated in T cells only: lck-Gli2ΔN2 transgenic mice express a truncated form of Gli2 that can function only as an activator of transcription, causing constitutive Hh-mediated transcription in all T cells (17).