With the ability to differentiate follicular adenoma from early-stage follicular carcinoma based on the location of GASP-1 overexpression in the follicles, and the size and shape of follicular cells, GASP-1 IHC can be used to differentiate follicular adenoma from follicular carcinoma when conventional H&E IHC gives inconclusive results. This evidence concerns the gene GPRASP1 and follicular thyroid adenoma.