SORL1 and Huntington disease: Figure 2C also shows that sortilin SORL1 and several tetraspanins are modulated by HD in the HD iPSC Consortium dataset. SORL1 gene expression was down-regulated to approximately a third of the control values, and reached statistical significance (Supplementary Table S3). Other sortilins showed a similar trend, but not significance in the RNA-Seq analysis (Supplementary Table S3). The HLA-B gene showed a decrease in the gene expression average of more than 50X in the HD iPSC Consortium dataset (Supplementary Table S3).