Kouprina N, Mullokandov M, Rogozin I, Collins K, Solomon G, Risinger J,Koonin E, Barrett JC. Larionov V. (2004) The SPANX gene family of cancer-testis specific antigens: rapid evolution, an unusual case of positive selection and amplification in African great apes and hominids. Proc Natl Acad Sci USA 101: 3077-3082.
Westbrook VA, Diekman AB, Klotz KL, Khole VV, von Kap-Herr C, Golden WL, Eddy RL, Shows TB, Stoler MH, Lee CY, Flickinger CJ, Herr JC. (2000)Spermatid-specific expression of the novel X-linked gene product SPAN-X localized to the nucleus of human spermatozoa. Biol Reprod 63: 469-481.
Westbrook VA, Schoppee PD, Diekman AB, Klotz KL, Allietta M, Hogan KT, Slingluff CL, Patterson JW, Frierson HF, Irvin WPJr, Flickinger CJ,Coppola MA, Herr JC. (2004)Genomic organization, incidence, and localization of the SPAN-X family of cancer-testis antigens in melanoma tumors and cell lines. Clin Cancer Res 10: 101-112.