When Türeci et al. initially identified SSX2 as the tumor antigen HOM-Mel-40, they also reported by RT-PCR and Northern blot that SSX2 mRNA was expressed in the following tumor tissues: melanoma (8/16), colorectal carcinoma (9/35), prostate cancer (5/25), breast cancer (7/36), hepatocellular carcinoma (3/6), glioma (2/23), lymphoma or leukemia (1/9), gastric carcinoma (1/12), and thyroid carcinoma tissue samples (2/4) (Table 2) [22]. This evidence concerns the gene SSX2 and breast carcinoma.