Identification of a gene for an ancient cytokine, interleukin 15-like, in mammals; interleukins 2 and 15 co-evolved with this third family member, all sharing binding motifs for IL-15Rα.
Dijkstra JM, Takizawa F, Fischer U, Friedrich M, Soto-Lampe V, Lefèvre C, Lenk M, Karger A, Matsui T, Hashimoto K. Immunogenetics. 2014 Feb; 66(2):93-103. Epub 2013 Nov 26.