KLF4 and neoplasm: A2BR knockdown did not affect tumor growth rate or sensitivity to paclitaxel (Figure 2A), but attenuated paclitaxel-mediated increases of the percentage of ALDH+ cells (Figure 2B), the number of mammosphere-forming cells (Figure 2C), and the mRNA expression of pluripotency factors NANOG, SOX2, and KLF4 (Figure 2D).