TGFB1 and Huntington disease: We found no differences in the levels of mRNA expression (supplementary material Fig. S7) for genes involved in cholesterol biosynthesis (Dhcr7a) and the TGF-β (Lefty1/2) pathway, which are dysregulated in HD R6/2 iPSCs (Castiglioni et al., 2012) and in HD knock-in ESCs (Jacobsen et al., 2011), respectively.