RIGI and melanoma: To explore the potential function of extratumoral RIG-I in regulating immunosurveillance against tumors, we s.c. injected murine colon carcinoma (MC38), lymphoma (EL4) or melanoma (B16F10) cells into syngeneic C57BL/6 WT (Rig-I+/+) or Rig-I–/– (KO) mice.