GDNF and Huntington disease: Different neurotrophic factors, such as BDNF, ciliary neurotrophic factor (CNTF), insulin-like growth factor-I (IGF-I), nerve growth factor (NGF), neurturin (NRTN) and glial cell line-derived neurotrophic factor (GDNF) have demonstrated a protective role in genetic and neurotoxin models of HD including the 2,3‐pyridine dicarboxylic acid (quinolinic acid, QA) and 3-nitropropionic acid (3-NP) models17–23.