All 24 fighters from UFC 155 were tested for performance-enhancing drugs, and all 24 came back clean.

Keith Kizer, the executive director of the Nevada Athletic Commission, confirmed the results with MMAjunkie.com.

Typically, just the main event and a select number of fighters are tested, but the commission has started testing all fighters who compete as of late.

Cain Velasquez became a two-time UFC heavyweight champion at UFC 155, defeating Junior dos Santos.