“He always had a smile and positive things to say about everything and everybody. He was a great drummer. He was a great caring person and a very spiritual soul. We will miss him so much and jam together again someday soon,” wrote bandmate Nikki Sixx on the group’s official Web site.

Published reports said that Castillo had suffered a ruptured stomach ulcer in 2000 and subsequently underwent emergency surgery. Two months after the operation, Castillo learned he had cancer. As of April, 2001, Castillo felt he had defeated cancer thanks to intensive radiation and chemotherapy sessions.