In October 2010, Herrera was the featured guest speaker at the Cardiology & Oncology International Symposium in Nashville, Tennessee. He had been diagnosed with a rare and usually fatal form of non-Hodgkins lymphoma in 1997, but underwent a stem cell transplant and, after a relapse, received a donor stem cell transplant that made medical history.
In remission for 10 years, he had also written the book The Cancer War, and testified before the U.S. Congress about the importance of federal funding for stem cell research.