| CPC C07K 14/54 (2013.01) [C07K 16/28 (2013.01); C07K 2319/33 (2013.01)] | 19 Claims | 
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               1. A human interleukin 21 (IL-21) variant, wherein the IL-21 variant comprises a polypeptide sequence as set forth in any one of SEQ ID NOs: 462, 463, 1192, 950, 933, and 894, or comprises one or more amino acid substitutions at one or more positions of SEQ ID NO: 1 selected from the group consisting of R38W and R105W. 
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