SPAG9 and breast cancer: One of the well-studied non-X linked CT antigens; SPAG9 was shown to be highly immunogenic in 67% of epithelial ovarian cancer [6], 77% in renal cell carcinoma [7], 80% in breast cancer [8], 80% in cervical cancer [9], 78% in thyroid cancer [10], 88% in chronic myeloid leukemia [11], 70% in colorectal cancer [12] and 72% in endometrial cancer [13].