ALDH1^high cells have a higher capacity for self-renewal.

<p>A, Colony formation assay. The number of colonies that were macroscopically visible, derived from the ALDH1^<b>high</b> and ALDH1^<b>low</b> cells of RD cells, was counted and scored at two months after planting. The mean ± SD was calculated from three independent experiments (nine wells for ALDH1^<b>high</b> or ALDH1^<b>low</b> cells in total). The ALDH1^<b>high</b> cells formed significantly more colonies than the ALDH1^<b>low</b> cells. B, Representative images of colonies are shown in the left panel (ALDH1^<b>high</b>) and right panel (ALDH1^<b>low</b>).