Fig4E. Copyright: Reprinted with permission from Elsevier from [doi:10.1016/j.ydbio.2006.08.008] Dev Biol 301: 205-17, Zuzarte-Luis V; Montero JA; Kawakami Y; Izpisua-Belmonte JC; Hurle JM, Lysosomal cathepsins in embryonic programmed cell death. Copyright 2007