PROM1 and malignant colon neoplasm: Using three independent primary spheroidal colon cancer cultures that expressed a Wnt reporter construct we observed high Wnt activity was associated with the cell surface markers CD133, CD166, and CD29, but not CD24 and CD44, while the original study found all five markers were correlated with high Wnt activity (Figure 2F; Vermeulen et al., 2010).