Although our follow-up period is too short to draw definitive conclusions and setting a cut-off value for the IFNAR2 mRNA ratio in order to select patients for IFN-α immunotherapy may be controversial, we are going to start a prospective study to assess the utility of IFNAR2 mRNA T/N ratios as a predictor of response to IFN-α immunotherapy in patients with RCC. Here, IFNAR2 is linked to renal cell carcinoma.