NCI is a member of the International Testicular Cancer Linkage Consortium (ITCLC), a group of over 30 institutions worldwide, which is mapping and cloning susceptibility genes that predispose to the development of familial testicular cancer. The large set of multiple-case families assembled by the ITCLC is also being leveraged for a series of genetic epidemiology studies. Investigators are conducting an analysis of testicular tumor pathology from both familial and sporadic testicular cancers, and several manuscripts are underway. NCI is collaborating with investigators from Norway and the United Kingdom on a quantitative assessment of the risk of cancers other than testicular cancer in high-risk families, and on a systematic pathology review of familial versus sporadic testicular cancers, seeking distinctive histopathology features in familial cases.