PECAM1 and esophageal squamous cell carcinoma: CD177 is also expressed by solid tumor TI Treg cells, which exhibited distinct transcriptional profiles characterized by enhanced immunosuppressive capabilities and were correlated with poor patient prognosis,including CRC (50), esophageal squamous cell carcinoma (ESCC) (51), hepatocellular carcinoma (HCC) (52), breast cancer, lung cancer, and melanoma (15, 53).CD177+ TiTregs may enable positive Treg cell subsets to interact with their ligand PECAM-1, and give these cells different functions.