In conclusion, the RET rearrangements, the RET/PTC3 in particular, were probably related to the disease duration and a corresponding stage of tumor progression, and the “successive waves of tumors in those exposed to high levels of fallout as children, each with different molecular, morphological, and clinical findings” [10] after the Chernobyl accident were largely determined by changing approach to screening and diagnostics, their improvement with time, and exhaustion by screening of the pool of undiagnosed cancers. This evidence concerns the gene RET and cancer.