Processing by proprotein convertases is required for glypican-3 modulation of cell survival, Wnt signaling, and gastrulation movements.

Glypican (GPC)-3 inhibits cell proliferation and regulates cell survival during development. This action is demonstrated by GPC3 loss-of-function mutations in humans and mice. Here, we show that the GPC3 core protein is processed by a furinlike convertase.