Moreover, Chen et al. (2014) demonstrated that IGF1R signaling activation in cancer cells in the presence of cancer-associated fibroblasts expressing IGF2 can induce Nanog expression and promote stemness, and that IGF2 secreted by cancer cells instigates fibroblasts and bone marrow-derived vascular progenitor cells to promote cancer progression (Xu W. et al., 2017). Here, IGF2 is linked to cancer.