GFRA4 and medullary thyroid gland carcinoma: In our cross-species comparisons, we identified notable gene overlaps between canine and human TC transcriptomes, including KIT, DUSP4, ETV4, INSR, and VEGFA in FTC and FOXA1, RET, ETV4, DUSP4, CALCA, CALCB, GFRA4, and SEMA3E in MTC.