THY1 and hepatocellular carcinoma: In gastrointestinal cancers, and particularly in hepatocellular carcinoma (HCC), increased levels of α-ASMA and THY1 expression in stroma and peritumoral tissue are associated with enhanced levels of placenta growth factor (PGF) expression, which, together with CD90, provide a strong correlation with tumor angiogenesis markers (CD31, CD34, CD105) [134].