MSLN and pancreatic neoplasm: Then IHC staining demonstrated a significant reduction in MSLN expression (p = 0.0047) and a substantial increase in CD3+CD8+ T cell infiltration (p = 0.0098) in tumor tissue after αMSLN treatment, indicating that αMSLN can effectively kill the cells with high expression of MSLN and modulate the immune microenvironment in pancreatic cancer (Figure 1I–L).