Immunostaining showed the tumor was negative for calretinin and D2-40, which completely ruled out mesothelioma, AE1/AE3 was partially positive, S100 was negative, smooth muscle actin (SMA) was focal positive, calponin was negative, epithelial membrane antigen (EMA) was weakly positive, CD68 was partially positive, and CD99 was positive. The gene discussed is MUC1; the disease is neoplasm.