Trained as a transplantation cardiologist, Dr. Zebra is really John Sotos, MD. He attended medical school and performed all of his clinical training at Johns Hopkins, where he was heavily influenced by two giants in American medicine: Dr. Victor McKusick and Dr. Philip Tumulty.

His pen-name comes from the title of his first book: Zebra Cards: An Aid to Obscure Diagnosis, which is a catalog of surprising signs and symptoms in clinical medicine, designed to stump even the most experienced physician. In 2005 he sent a copy of Zebra Cards to the producers of the television show House, MD and was thereafter hired as a medical technical advisor for the remaining six seasons of the show's run.

His interest in presidential health began in medical school, after reading about the post-shooting clinical course of President James Garfield. The doctorzebra.com web site was launched in 2000. Early on, it twice won the twice won the Yahoo! Website of the Day award, and was even anthologized in a college textbook of English. It is often referenced by the media, such as the New York Times.

Beyond the doctorzebra web site, Dr. Sotos has made four original contributions to presidential health:

• Making the case in a 2003 peer-reviewed journal article that President Taft was impaired by severe obstructive sleep apnea while president.
• Making the case in a 2008 book, The Physical Lincoln, that President Abraham Lincoln was afflicted with multiple endocrine neoplasia type 2B and, if he had not been shot, would have soon died in office from the disease.
• Making the case in a 2016 peer-reviewed journal article that untreated pernicious anemia caused First Lady Mary Lincoln's tragic and well-known mental troubles, as well as her numerous physical ailments, culminating in her death at the young age of 63.
• Making the case in a 2021 peer-reviewed publication that the United States should require presidential candidates to disclose any health history that would medically disqualify them from military service, specifically, from service as a military air traffic controller.

All of this has led to coverage by virtually every English-speaking news organization in the world, from National Geographic to CBS News to Nature to Good Morning America to Saturday Night Weekend Update. Dr. Sotos has also been interviewed on current matters of presidential health by outlets such as CNN (on camera), NPR, Vanity Fair, and the Washington Post.

Currently Dr. Sotos is CEO of Expertscape Inc. and a retired US Air Force flight surgeon. The astronaut section of doctorzebra.com arose from his nearly successful attempt to become an astronaut. His personal web site is sotos.com.