The present invention generally relates to mutant interleukin-2 polypeptides that exhibit reduced affinity to the α-subunit of the IL-2 receptor, for use as immunotherapeutic agents. In addition, the invention relates to immunoconjugates comprising said mutant IL-2 polypeptides, polynucleotide molecules encoding the mutant IL-2 polypeptides or immunoconjugates, and vectors and host cells comprising such polynucleotide molecules. The invention further relates to methods for producing the mutant IL-2 polypeptides or immunoconjugates, pharmaceutical compositions comprising the same, and uses thereof.本發明概言之係關於對於IL-2受體之α-亞單位展現減小親和力之突變介白素-2多肽,其用作免疫治療劑。此外,本發明係關於包括該等突變IL-2多肽之免疫偶聯物,編碼該等突變IL-2多肽或免疫偶聯物之多核苷酸分子,及包括該等多核苷酸分子之載體及宿主細胞。本發明進一步關於產生該等突變IL-2多肽或免疫偶聯物之方法,包括其之醫藥組合物,及其用途。