PECAM1 and hepatocellular carcinoma: Key markers, such as PTPRC, CD3E, CD4, CD79A, and CD3G in immune cells, EPCAM and KRT19 in epithelial cells, and MME and PECAM1 in stromal cells (Fig. 2E), were identified, providing crucial insights into hepatocellular carcinoma progression and immune response mechanisms [18, 19].