PECAM1 and hepatocellular carcinoma: A recent study has shown that CD90 positive CAFs have a strong correlation with PIGF expression in HCC tissues, and highly expressed of CD90 and PIGF in CAFs were related to angiogenesis-related markers in vascular endothelial cells, such as CD31, CD34, and CD105, thus to facilitate the angiogenesis of HCC [96].