In the United States, KS is most often seen in patients with AIDS and patients on immunosuppressants after organ transplantation. KS can also be classic (older Mediterranean men) or endemic (young men in sub-Saharan Africa). KS is caused by Kaposi's sarcoma-associates herpesvirus (KSHV), which promotes oncogenesis. KS cannot be cured, but treatment can result in improvement or disease stabilization. Current therapies improve the immune system or target KSHV. Therapies that modulate KSHV-mediated signaling are being studied.