IL2 and cancer: Previous evidence has indicated an association of hyponatremia with poor outcomes in various cancers including RCC.14,15,16,17 Hyponatremia has been shown to be associated with negative outcomes both in patients with localized RCC and in patients with mRCC receiving several types of drugs, including low-dose interleukin-2, interferon-α, mammalian target of rapamycin inhibitors, or TKIs.18,19 However, there is a lack of data regarding the prognostic role of hyponatremia in patients with RCC receiving ICIs.