Immunohistochemically, tumor cells were positive for AE1/AE3, EMA, CK19, CK7, CD10, and calretinin (Fig. 4c), partly or weakly positive for CK5/6, D2-40, vimentin, and WT-1, and negative for HepPer1, chromogranin A, synaptophysin, CEA, inhibin α, MUC1, melan A, HMB45, CA19-9, ER, PgR, CD34, bcl-2, and β-catenin (Fig. 4d, e). The gene discussed is PGR; the disease is neoplasm.