In March 2011, a major earthquake and tsunami hit the Fukushima Daiichi nuclear plant in Japan, causing the reactor to melt down. Five years later, children living near the plant were reported to have rates of thyroid cancer 20 to 50 times that of other children in Japan.1 This finding, however, appeared to stem from a systematic thyroid ultrasonographic screening program—one that did not extend to the rest of Japan. Other investigators applying the same screening protocol to children in other Japanese regions found that the rate of thyroid cancer detected by screening did not differ meaningfully from that in the Fukushima region.2 In other words, the apparent epidemic was the result of screening, not radiation.