Inclusion Criteria:
1. Aged 18-75 years (≥18 and ≤75 years), either sex;
2. The subject voluntarily participates in the study and provides written informed consent signed by the subject or his/her legally authorized representative;
3. Histopathologically confirmed unresectable, locally advanced, recurrent, or metastatic solid malignant tumor; according to the AJCC TNM staging system (8th edition, 2017), subjects diagnosed with stage III or stage IV solid malignant tumors;
4. Presence of measurable and evaluable lesions according to RECIST v1.1;
5. Positive MSLN expression in tumor tissue confirmed by immunohistochemistry (IHC);
6. The subject must have received standard first-line therapy and has experienced disease progression or is intolerant to such therapy;
7. The subject is not suitable for curative treatment modalities such as definitive chemoradiotherapy and/or surgery/immune checkpoint inhibitors, or refuses surgical resection;
8. No antibody-based therapy administered within 2 weeks prior to cell therapy;
9. ECOG performance status 0-2;
10. No contraindications to peripheral blood leukapheresis;
11. Estimated life expectancy ≥ 3 months.
Exclusion Criteria:
1. History of allergy to any component of the cell product;
2. Any of the following hematologic abnormalities on complete blood count (CBC): WBC ≤ 1 × 10\^9/L, absolute neutrophil count (ANC) ≤ 0.5 × 10\^9/L, absolute lymphocyte count (ALC) ≤ 0.5 × 10\^9/L, or platelets (PLT) ≤ 25 × 10\^9/L;
3. Any of the following laboratory abnormalities, including but not limited to: serum total bilirubin ≥ 1.5 mg/dL; serum ALT or AST \> 2.5 × ULN; serum creatinine ≥ 2.0 mg/dL;
4. NYHA class III or IV heart failure per the New York Heart Association functional classification, or left ventricular ejection fraction (LVEF) \< 50% on echocardiography;
5. Abnormal pulmonary function with oxygen saturation (SpO₂) \< 92% on room air;
6. History of myocardial infarction, coronary angioplasty or stenting, unstable angina, or other clinically significant severe cardiac disease within 12 months prior to enrollment;
7. Grade 3 hypertension with poor blood pressure control despite medical treatment;
8. History of traumatic brain injury, disturbance of consciousness, epilepsy, or severe cerebral ischemic or hemorrhagic disease;
9. Presence of autoimmune disease, immunodeficiency, or other conditions requiring immunosuppressive therapy;
10. Presence of uncontrolled active infection;
11. Prior treatment with any CAR-T cell product or other genetically modified T-cell therapy;
12. Receipt of a live vaccine within 4 weeks prior to enrollment;
13. Positive test results for HIV, HBV, HCV, and TPPA/RPR, and/or HBV carriers;
14. History of alcohol abuse, illicit drug use, or psychiatric disorders;
15. Participation in any other clinical study within 3 months prior to enrollment;
16. Female subjects meeting any of the following:
1. pregnant or breastfeeding; or
2. planning pregnancy during the study period; or
3. of childbearing potential and unable/unwilling to use effective contraception;
17. Any other condition that, in the opinion of the investigator, makes the subject unsuitable for participation in this study.
