RAG1 and melanoma: In particular, overexpression of INHBA in syngeneic grafts of mouse B16-F1 or YUMM3.3 mouse melanoma, or inhibition of endogenous Activin-A in syngeneic iBIP2 melanoma grafts by a ligand trap revealed that Activin-A secretion by the cancer cells stimulates both primary and metastatic tumor growth specifically in immunocompetent hosts, but not in nu/nu or Rag1-/- mice lacking adaptive immunity (16, 17).