The Exploratory Study on the Biological Function of Dendritic Cells In Vivo Supported by Nicotinamide Mononucleotide (Vital NAD)

Inclusion Criteria: * 1\. 18-80 years old, weight ≥ 40kg. * 2\. Patients with malignant solid tumors diagnosed by histology or cytology, who underwent radical resection and completed standard postoperative adjuvant therapy. * 3\. Estimated survival time ≥ 6 months. * 4\. ECOG score 0-1. * 5\. Adequate venous channels, there is no contraindication for peripheral blood monocyte collection. * 6\. Good function of organs and bone marrow. Exclusion Criteria: * 1\. Diabetes. * 2\. Premenopausal or menopause \<1 year. * 3\. Persons who have received hormone replacement therapy within the past 6 months. * 4\. Persons who take vitamin B supplementation and are not willing to discontinue supplementation for 3 weeks before and during the entire study period. * 5\. Unstable weight (\>3% change during the last 2 months before entering the study). * 6\. Significant organ system dysfunction or disease. * 7\. Polycystic ovary syndrome. * 8\. Major psychiatric illness. * 9\. Use of medications known to affect study outcome measures (e.g., steroid) or increase the risk of study procedures (e.g., anticoagulants) that cannot be temporarily discontinued for the study. * 10\. Metal implants. * 11\. Persons who consume \>14 units of alcohol per week. * 12\. Unable or unwilling to follow the study protocol or who, for any reason, is considered an inappropriate candidate for the study by the research team.