IGF1 and Parkinson disease: Following dopamine neuron damage in PD, microtubule-associated LC3-II and α-Syn are significantly up-regulated and p62 down-regulated, whereas insulin-like growth factor-1 (IGF-1) inhibits autophagy via the IGF-1R/PI3K-AKT-mTOR pathway, thereby attenuating neurotoxicity (Wang et al., 2020c).