For nearly a decade, the immunologist and biochemist William Parker has tried, with little success, to persuade other scientists to take seriously his theory that acetaminophen—better known by the brand name Tylenol—is the primary cause of autism. Researchers have long failed to find a causal link between autism and any medication, and these days, most of them believe that a change in diagnostic criteria is largely behind the dramatic uptick in autism rates over the past 30 years. But late last month, Parker received a phone call from Health Secretary Robert F. Kennedy Jr., who wanted to learn more about his work. In fact, he’s heard from Kennedy several times since then. Parker also spoke recently with Jay Bhattacharya, the director of the National Institutes of Health. To hear Parker tell it, the nation’s top health officials have taken great interest in his ideas.