Since definite histopathological features of malignant transformation (interstitial and vascular invasions) are rarely found in a critical biopsy specimen, next to the demonstration of disturbed trabecular architecture, the diagnosis of well-differentiated HCC may be supported by diffuse capillarization of the sinusoids in HCC as detected by CD34 immunohistology [22]. The gene discussed is CD34; the disease is hepatocellular carcinoma.