KLF4 and skin cancer: Therefore, we examined whether VEGF-C affects cancer stemness in skin cancer cells and found that knockdown of VEGF-C significantly decreased the expression of the CSC markers SOX2, OCT4, KLF4, NANOG, CD133, CD34 and CD44 as well as ALDH activity, which is a hallmark of CSCs (Figure 2a-2h).