This invention provides for a fusion protein between an IL2αβγ Selective Agonist protein (IL2 Selective Agonist) and a IgG Fe protein. The IL2 Selective Agonist moiety provides a therapeutic activity by selectively activating the IL2αβγ form of the receptor, thus selectively stimulating Tregs. The Fe moiety provides a prolonged circulating half-life compared to the circulating half-life of IL-2 or an IL2SA protein.