DNA methylation changes were recorded in HD-hiPSCs, compared to hiPSCs obtained from healthy controls, with increased methylation during their differentiation to striatal neurons [180]; pathways that were mostly affected were associated with neuronal development and differentiation (e.g., axon guidance, WNT and TGF-β pathways, SMAD and GABA receptor signaling, etc.); additionally, clear hypermethylation at the promoter sequence of the WDR5 (WD repeat-containing protein 5) gene that codes for a chromatin remodeling protein was identified in HD-hiPSCs [180]. The gene discussed is TGFB1; the disease is Huntington disease.