Boxing star Ruben Castillo -- who fought in four world championship bouts -- passed away after a battle with cancer.
He was 68.
Castillo -- famously known as the Conquistador -- died on Wednesday in Beaumont, California, and was surrounded by his loved ones. After the sad news, tributes flooded social media honoring the featherweight fighter, including a video message from WBC President Mauricio Sulaiman.
"I'm so deeply saddened by the passing away of Ruben Castillo," Sulaiman said, "What a wonderful man.