EGF and sarcoma: Although examples of such autonomy exist in the case of the Platelet-derived growth factor and TGFα by glioblastomas and sarcomas, respectively, and MDA MB-231 cells are known to secrete EGF (64) and depend on its autocrine (not paracrine) sensing/signaling for metastatic progression (65), autocrine autonomy in the EGF/EGFR pathway had not been described previously and mechanisms that support such sense-and-secrete loops in eukaryotes had remained elusive.