For example, even though no infectious HERV particles have been detected to date, HERV-K (HML-2) have been found to produce viral like particles (VLP) in the tumor tissues of patients with breast cancer, leukemia, lymphoma, melanoma, and teratocarcinoma, and in the blood of HIV-infected individuals [10,14,15,18–26]. The gene discussed is CLEC10A; the disease is teratocarcinoma.