Together, these findings indicate that transient overexpression of miR-29a can lower PMP22 mRNA (Fig. 4) and protein (Fig. 5) levels in CMT1A patient fibroblasts by about 25–40%, which is within the desirable therapeutic window for this dosage-sensitive gene. The gene discussed is PMP22; the disease is Charcot-Marie-Tooth disease type 1A.