CD34 and Friedreich ataxia: In 2 patients with FA, we were able to demonstrate an elevated proportion of CD34+ cells with high levels of NKG2D-Ls in periodic BM aspirations spaced 6 months to 2 years apart, revealing that the expression of NKG2D-Ls in FA HSPCs was not a sporadic or transient phenomenon (Table 1 and Figure 3B).