C3 and Huntington disease: ClueGO overrepresentation and enrichment analysis of transcripts significantly dysregulated in both HD iPSC lines revealed positive regulation of humoral immune response and ion transport by P-type ATPases as GO terms with the lowest p value (Figure 6 and Supplementary Table S7) C3 gene, which is highlighted as associated with the first biological process, is in the top 10 dysregulated transcripts in both HD iPSC lines.