The role of OSM in testicular cancer has not been extensively studied, however De Miguel et al. in 1999 evaluated the presence of OSM in Leydig cells (cells in the testes responsible for testosterone production) as well as in various testicular carcinomas, including carcinoma-in-situ (CIS), germ cell tumors, and benign functioning Leydig cell tumors (148). The gene discussed is OSM; the disease is in situ carcinoma.