Apart from the aforementioned discussion on xenotransplantation and migratory/invasive potential, comparative results between the epithelioid and fibroblastoid subsets with respect to additional test parameters (such as phenotyping, in vitro growth characteristics, anchorage-independent colony forming ability, and expression of CD105, one of the known RCC stem cell markers [21]) are summarized in Table 2. The gene discussed is ENG; the disease is renal cell carcinoma.