Immunohistochemical examinations showed that the tumor cells were positive for ERG (Fig. 4A), CD34, CD31 (Fig. 4B), and vimentin, whereas CK (AE1/AE3), EMA, CK7, HMB45, SMA, CD117, Dog-1, and S-100 were negative; Ki-67 labeling index was 30%. The gene discussed is PECAM1; the disease is neoplasm.