HTT and Huntington disease: We showed that mHTT is associated with increased protein expression of sortilin SORCS1 in ST14A cells (Figure 2A), in agreement with our previous report for mRNA molecules of SORCS1 and that there exists allele association (also known as Linkage Disequilibrium) of regions near SORT1, SORL1, SORCS1, SORCS2 and SORCS3 with gene variants in the region of HTT gene specifically in human HD cases (Figure 5).