In HD PBMC pre-treated with Pep3 and subsequently stimulated for 4 days with anti-CD3/CD28 beads, the percentage of CD8+ Treg significantly increased upon Pep3 treatment in a dose dependent manner between 10 and 15μM (Fig 1a; S2 Fig) compared to untreated stimulated cells. The gene discussed is VPS18; the disease is Huntington disease.