HLA-DQA1 has been previously reported as a candidate RNA biomarker in human lymphocyte microarray data from HD patients, ranking among the top most changed genes.9 The highest expressed significant gene was S100 calcium binding protein A9 (S100A9) with a log2 expression value of 11.7, while the lowest expressed significant gene was sperm acrosome associated 3 (SPACA3) with a value of −2.8, indicative of the high dynamic range of the sequencing platform (211.7−(−2.8)=23 170 fold). Here, S100A9 is linked to Huntington disease.