PDGFA and cancer: Moreover, 20 ng/mL of PDGF-AA added to the HCT116 cells was capable of inducing the expression of not only LGR5 (Fig. 2e) but also β-catenin (Fig. 2f), a protein stabilized by Wnt, indicating that PDGFA overexpression in the cancer stem-like tumorspheres played a major role in inducing the activation of the Wnt signaling pathway.