The incidence of childhood cancers has been steadily rising for several decades, to such an extent that cancers in young people now have their very own day in the limelight: International Childhood Cancer Day (February 15). For American children ages one through 14, cancer is the top disease-related cause of death, second only to accidents among all causes of childhood mortality. Leukemia and malignancies of the central nervous system are the most common types of childhood cancers. A recent opinion piece in The Hill points out that autism spectrum disorders (ASDs) have increased in lockstep with pediatric cancers. One in thirty-six (2.76%) children aged three-17 had an ASD diagnosis as of 2016, compared to one in 10,000 children in the 1970s. The parallel rise in the two conditions is not a fluke—environmental toxins are widely known to “initiate or aggravate various neurological disorders [and] carcinomas.” Although the National Cancer Institute (NCI) views environmental causes of childhood cancers as “difficult to identify,” one route of exposure to heavy metals and other toxic substances that begins prenatally and continues through adolescence is sitting in plain sight: the bloated U.S. vaccine schedule.