MTOR and juvenile Huntington disease: For example, the well-known mammalian target of rapamycin (mTOR) inhibitor rapamycin, and recently identified active autophagic herbal compounds onjisaponin B (Wu et al., 2013), neferine (Wong et al., 2015), hederagenin and α-hederin (Wu et al., 2017), can induce the mTOR-dependent autophagy with an accelerated clearance of mutant huntingtin fragments in Huntington's disease models (Ravikumar et al., 2004).