CASP3 and Huntington disease: Consistent with previous report, the protective effect of BMSC-CM against HD-induced apoptosis was also observed in ventral spinal cord 4.1 (VSC4.1) cells, a cell line of dorsal motor neurons, by showing decreased number of TUNEL-positive cells and activity of caspase-3 compared with HD alone group (Fig. 4A–C,F).