Veteran UFC fighter Jim Miller is set to make his long-awaited return to the Octagon at UFC 328, and fans now understand why he's been away. The 41-year-old, who has been with the promotion since 2008 and boasts an incredible 46 UFC fights (57 overall in his MMA career), has been fighting a different kind of battle—one far more personal than any inside the cage.

Miller, who has fought on historic cards like UFC 100, UFC 200, and UFC 300, has his sights set on hitting 50 UFC fights before retiring. That makes his upcoming bout against Jared Gordon at UFC 328 a must-watch, especially after learning what he's overcome in the past year.

In an emotional interview with BJPenn.com's Cole Shelton, Miller revealed that his 14-year-old son was diagnosed with Rhabdomyosarcoma—a rare and aggressive childhood cancer. "He had a tumor tucked into his sinus and eye socket," Miller explained. "Frontally, location-wise, it was probably in the best spot it could be. It popped right out when he did the biopsy. But he still had to go through two rounds of chemotherapy and a round of radiation."

The radiation treatments required daily trips to Rutgers, an hour-and-a-half from their home, for five weeks straight. Miller, who was training for a fight at the time, put everything on hold. "The ability to do that and move my schedule around... I'm glad I'm a fighter, I'm glad I chose this road, so I could be there for my son and help him through his struggles," he said.

The news comes with a silver lining: Miller's son is now officially cancer-free and has had his port removed. "He kicked its ass," Miller said proudly. "We had a really tough six months... I couldn't be happier with the way things turned out. He's amazing, he's an amazing young man, he makes me proud every day."

As Miller steps back into the cage at UFC 328, he carries more than just his own fighting spirit—he carries the strength of a father who faced his toughest opponent yet and won.