Beyond established driver mutations such as BRAF, RAS, RET/PTC, and TERT promoter alterations, environmental and lifestyle factors, including ionizing radiation exposure, iodine imbalance, and endocrine-disrupting chemicals, may contribute to thyroid tumorigenesis by inducing oxidative stress, DNA strand breaks, and epigenetic dysregulation within follicular cells. Here, RET is linked to thyroid gland disorder.