GPC3 and cancer: GPC3 plays important roles in tissue morphogenesis and homeostasis during development, e.g., developmental outgrowth and dysplastic kidneys of Simpson-Golabi-Behmel syndrome [17], via Wnt/JNK signaling [18] or FGF signaling pathways [19], in the processes of chondrogenesis and osteogenesis via the morphogenetic protein signaling pathway [20], and several malignancies as a cancer suppressor gene through a suppression of PI3K/Akt pathways and a stimulation of P38/MAPK pathway [21] (Fig. 1).