In July 2024, 11-year-old River Brennan noticed lumps on the right side of his neck and showed them to his parents. “I hope I don’t have cancer,” he told them. “I looked at him and said, ‘Dude, you don’t have cancer,’ ” remembers his father, Shaun Brennan, 47, owner of Dan Electro’s, a music venue in Houston’s Heights neighborhood. “I was absolutely wrong.”