As reviewed by Ch’ng and Kumanogoh [6], several studies have described a role for Sema4D and plexin-B1 in tumor progression, including soft tissue sarcomas, B-cell chronic lymphocytic leukemia, renal cell carcinoma, breast and ovarian carcinomas, prostate adenocarcinoma, and pancreatic cancer. The gene discussed is SEMA4D; the disease is neoplasm.