PRDM9 and thyroid cancer: That high frequency of mutations detected for the chromatin modifiers (e.g., SWI/SNF subunits and histone methyltransferases) and transcription-associated regulators (e.g., MED12, RBM10, and EIF1AX) in ATC and fatal forms of non-ATC suggested the critical roles of chromatin/transcription regulators in the development of high-mortality thyroid cancer.