As expectedly, nuclear p-S727 STAT3 positive cells were found in the adrenocortical adenoma components in Cases 1 and 3 (Case 3 > Case 1) in association with FGFR4 variant status, while no tyrosine phosphorylation of STAT3, a downstream signal of wild-type FGFR4, was found in any tumors. Here, STAT3 is linked to adrenal cortex adenoma.