Inclusion Criteria:
1. Voluntarily sign a written informed consent;
2. Age ≥18 years old, ≤70 years old, male and female;
3. Expected survival ≥ 3 months;
4. The Eastern Cancer Collaboration (ECOG) physical fitness score was 0-1;
5. Biopsy specimen or pathological wax section test (within 3 years before the signing of informed consent) : Target protein test is positive;
6. At least one measurable lesion according to RECIST v1.1 solid tumor evaluation criteria;
7. Patients with recurrent/metastatic refractory digestive tract tumors (esophageal, gastric, pancreatic, or colorectal cancer) who have previously received second-line or above standard treatment failure or intolerance;
8. It is possible to establish a vein access for simple or intravenous blood collection, and there are no other contraindications for blood cell separation;
9. having adequate organ and bone marrow function, as defined below: Blood routine examination Neutrophil count (NEU #) ≥1.0×10\^9/L Platelet count (PLT) ≥80×10\^9/L Hemoglobin concentration ≥90g/L Liver function: subjects without liver metastases Aspartate aminotransferase (AST) ≤2.5× Upper Limit of Normal (ULN) Alanine aminotransferase (ALT) ≤2.5× Upper Limit of Normal (ULN) Total bilirubin (TBIL) ≤1.5×ULN Liver function: Subjects with liver metastases Aspartate aminotransferase (AST) ≤5× Upper limit of normal (ULN) Alanine aminotransferase (ALT) ≤5× Upper limit of normal (ULN) Liver function: Subjects with liver metastases or Gilbert syndrome Total bilirubin (TBIL) ≤2×ULN renal function Creatinine clearance (CCR) ≥50 mL/min Coagulation function International Standardized ratio (INR) ≤1.5×ULN Activated partial thromboplastin time (APTT) ≤1.5×ULN
10. Toxic side effects left over from previous anti-tumor therapy (radiotherapy, chemotherapy, targeted therapy, etc.) ≤ grade 1 (CTCAE 5.0);
11. During the study period and for 6 months after the end of dosing, fertile subjects (both male and female) must use effective medical contraception. For female subjects of reproductive age, a pregnancy test should be performed within 72 hours before the first dose and the result is negative.
Exclusion Criteria:
1. Active central nervous system metastases (except those stable after treatment);
2. HIV positive, HBsAg positive, HBV DNA copy number positive (quantitative detection ≥1000cps/ml), HCV antibody positive and HCV RNA positive;
3. Patients with mental or mental illness who cannot cooperate with treatment and efficacy evaluation;
4. Subjects with severe autoimmune diseases and long-term use of immunosuppressants;
5. Active or uncontrolled infections requiring systemic treatment during the 14 days prior to enrollment;
6. Any unstable systemic disease (including but not limited to) :
Active infections (except local infections); unstable angina pectoris; cerebral ischemia or cerebrovascular accident (within 6 months prior to screening); myocardial infarction (within 6 months before screening); Congestive heart failure (New York Heart Association \[NYHA\] classification ≥III); Severe arrhythmias requiring medical treatment; have a heart condition that requires treatment or uncontrolled hypertension after treatment (blood pressure \> 160mmHg/100 mmHg);
7. dysfunction of important organs such as lung, brain and kidney;
8. The subject has undergone major surgery or severe trauma within 4 weeks prior to receiving cell therapy, or is expected to undergo major surgery during the study period;
9. Received any systemic chemotherapy, immunotherapy, or small molecule targeted therapy within 1-2 weeks prior to anapheresis or within 5 half-lives, whichever is shorter;
10. The subject currently has or has had other malignant tumors that cannot be cured within 3 years, except cervical carcinoma in situ or basal cell carcinoma of the skin, and other malignant tumors with disease-free survival of more than 5 years;
11. Received chimeric antigen receptor modified T cells (including CAR-T, TCR-T) within six months;
12. Graft-versus-host disease (GVHD);
13. Participants who were receiving systemic steroid therapy prior to screening and who were determined by the investigator to require long-term use of systemic steroid therapy during treatment (except for inhalation or topical use); And subjects treated with systemic steroids within 72 h prior to cell transfusion (except for inhalation or topical use);
14. Severe allergies or history of allergies;
15. Subjects requiring anticoagulation therapy;
16. Pregnant or breastfeeding women, or have a pregnancy plan within six months (for both men and women)
17. Researchers believe that there are other reasons for not being included in the treatment.
