CA13 (carbonic anhydrase 13) is a cytoplasmic enzyme that catalyzes the reversible hydration of carbon dioxide, functioning as a carbonate dehydratase with protein binding capabilities 1. Beyond its metabolic role, CA13 appears to function as a tumor suppressor in breast cancer, where overexpression suppresses migration, invasion, and bone metastasis while reducing VEGF-A and M-CSF expression 1. Clinically, low CA13 expression correlates with significantly shorter overall survival and disease-free survival in breast cancer patients, suggesting its potential as a prognostic biomarker 1. CA13 also serves as a biomarker in multiple disease contexts: it functions as a senescence-linked circulating biomarker that changes with aging and responds to senolytic drug treatments in mice 2, and elevated serum CA13 levels characterize both inflammatory bowel disease and irritable bowel syndrome patients compared to healthy individuals 3. Additionally, CA13 is identified as a target gene for anti-epileptic drugs, with genetic associations to serum vitamin D levels 4. The protein's involvement spans from basic cellular metabolism to complex disease processes including aging, cancer metastasis, and inflammatory conditions, indicating multifaceted biological roles beyond carbonic anhydrase activity.