Background: Numerous antibody biomarkers have been reported for cancer and atherosclerosis-related diseases. The major complications of atherosclerosis and diabetes mellitus (DM) are acute ischemic stroke (AIS), cardiovascular disease (CVD), and chronic kidney disease (CKD). Cancer development is accompanied by arterial disorders such as angiogenesis and atherosclerosis, and DM is a risk factor for certain cancers. Atherosclerosis-related diseases and cancers are therefore interrelated and could be detected by a common biomarker.Methods: We employed the protein array method for the initial screening of antigens and employed the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) to evaluate antibody levels in serum samples.Results: The protein array identified KIAA0513 as an antigen recognized by serum IgG antibodies in the sera of patients with atherosclerosis. We then prepared recombinant glutathione S-transferase-fused KIAA0513 protein. AlphaLISA showed significantly higher serum antibody levels against KIAA0513 protein in patients with AIS, transient ischemic attack, DM, CVD, obstructive sleep apnea syndrome (OSAS), CKD, and solid cancers, such as esophageal, gastric, colon, lung, and breast cancer, than in healthy donors. A receiver operating characteristic (ROC) analysis revealed that the highest areas under the ROC curves of anti-KIAA0513 antibodies were for esophageal cancer, nephrosclerosis-type CKD, and DM. Spearman’s correlation analysis revealed that serum anti-KIAA0513 antibody levels were associated with maximum intima-media thickness and plaque score, which are indices of atherosclerosis and stenosis.Conclusion: Serum anti-KIAA0513 antibody markers appear to be useful for diagnosing AIS, TIA, DM, CVD, OSAS, CKD, and solid cancers and might reflect common arterial alterations leading to atherosclerotic and cancerous diseases.