AREG and skin neoplasm: Along the same lines, we also highlight activinβA (Inhba) because this member of the TGF-β superfamily was shown to increase malignancy and metastatic spread of skin tumors (27); semaphorins (Sema6d, Sema4d), which can shape the tumor microenvironment (28); and ligands of the EGF receptor (Areg, Ereg).