UFC on ESPN 25: The Korean Zombie vs. Ige was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on June 19, 2021 at the UFC Apex facility in Enterprise, Nevada, part of the Las Vegas Metropolitan Area, United States. A featherweight bout between former UFC Featherweight Championship challenger Chan Sung Jung and Dan Ige served as the event headliner.

UFC on ESPN 25: Korean Zombie vs Ige

UFC Fight Night 184: Overeem vs. Volkov was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on February 6, 2021 at the UFC Apex facility in Enterprise, Nevada, part of the Las Vegas Metropolitan Area, United States. A heavyweight bout between the 2010 K-1 World Grand Prix Champion, former Strikeforce Heavyweight Champion and UFC Heavyweight Championship challenger Alistair Overeem and former Bellator Heavyweight World Champion Alexander Volkov served as the event headliner.