MSLN (mesothelin) is a cell surface glycoprotein that plays significant roles in cancer progression and serves as a promising therapeutic target. MSLN promotes tumor metastasis through multiple mechanisms, including facilitating blood-brain barrier penetration in non-small cell lung cancer by activating MET signaling via the JNK pathway 1. In colorectal cancer, MSLN expression is upregulated by WNT5A signaling from cancer-associated fibroblasts, promoting epithelial-mesenchymal transition and tumor invasiveness 2. As a therapeutic target, MSLN is overexpressed in various solid tumors including ovarian cancer, pancreatic cancer, hepatocellular carcinoma, and mesothelioma 345. MSLN-directed CAR-T cell therapies have shown promising results in preclinical and early clinical studies, with enhanced efficacy when combined with IL-7 and CCL19 secretion or modified CD3ζ signaling domains 467. The protein's tumor-specific expression pattern makes it an attractive target for immunotherapy approaches, including CAR-T cells and bispecific antibodies, particularly for treating solid tumors where conventional therapies have limited efficacy 85.