Aion (Korean: 아이온: 영원의 탑, also known as Aion: The Tower of Eternity) in Japan, is a massively multiplayer online role-playing game (MMORPG) released by NCsoft, a major Korean game developer. The game combines PvP and PvE (a concept the developers call PvPvE) in a fantasy game environment. As of May 20, 2009, Aion has 3.5 million subscribers in Asia. AION's first major expansion was released to North America and Europe on September 7, 2010 under the name AION: Assault on Balaurea.