SSX2 and prostate cancer: JNJ-64041809 (JNJ-809) is a LADD Lm-based immunotherapy that encodes and expresses 4 antigens relevant to prostate cancer: prostatic acid phosphatase (PAP) [28], prostate-specific membrane antigen (PSMA) [29], synovial sarcoma X breakpoint 2 (SSX2) [30, 31], and homeobox protein NKX3.1 [32–34].