IFNB1 and melanoma: After local injection of IFN-β (106 U/injection 5 times over 5 successive days) into B16-F10 melanoma tumors in C57BL/6 mice, analysis of interstitial infiltrate showed 21–50% T cells and <5% NK cells; similarly, tumor nest infiltrate contained 5–20% T cells compared to 0% NK cells, indicating that the immune response was primarily T-cell-mediated [57].