SYCP1 and synovial sarcoma: With a new method called serological identification of antigens by recombinant expression cloning (SEREX) (13), many more CTAs were uncovered, such as synovial sarcoma, X breakpoint 2 (HOM-MEL-40/SSX2) (13), New York’s esophageal squamous cell carcinoma 1 (CTAG1B, NY-ESO-1) (14, 15), synaptonemal complex protein 1 (SCP1) (16), and CT7 (17).