Zamecnik and Michal [59] found immunoreactivity for HMB-45 in four distinctively hyalinized epithelioid mesenchymal tumors of the uterus, but all four cases were negative for the other three melanogenesis markers tested (Melan-A, tyrosinase and micropthalmia transcription factor). This evidence concerns the gene MLANA and mesenchymal cell neoplasm.