Evaluation of CD13 expression could be of great help in dealing with such difficult cases because (i) the combination of CD13 and EMA can potentially facilitate the diagnosis of meningioma, as all of the meningiomas tested expressed either one of the two markers or both, and (ii) none of the schwannomas nor of the SFT/HCPs showed positive immunohistochemical staining for CD13. The gene discussed is MUC1; the disease is schwannoma.