The alteration of mRNA levels of constituents of the Arp2/3 complex and actin-related proteins further substantiates the identification of CDC42 as an important hub gene in the brain since CDC42 can activate the Arp2/3 complex through Wiskott-Aldrich syndrome proteins [42] such as WAS, WASF1, WASF2, WASF3, and WASL that appeared to be neither robustly altered in the brain nor the blood of HD patients. This evidence concerns the gene CDC42 and Huntington disease.