PROBLEM TO BE SOLVED: To provide a novel target for production of immune-based or non-immune-based therapeutics and for disease diagnosis.SOLUTION: The invention provides therapeutic antibodies against VSIG1, ILDR1, LOC253012, AI216611, C1ORF32 or FXYD3 antigen, as well as diagnostic and therapeutic usages, where the antigens are predicted as co-stimulatory family members and differentially expressed in cancers including lung cancer, ovarian cancer and colon cancer. Also provided is a use method of these antibodies to modulate B7 co-stimulation and for related therapies such as the treatment of autoimmune diseases. The invention also provides finding of ectodomain polypeptides of VSIG1 and variants thereof, FXYD3 and variants thereof, ILDR1 and variants thereof, LOC253012 and variants thereof, AI216611 and variants thereof and C1ORF32 and variants thereof, which are suitable targets for immune therapy, cancer treatment and drug development.【課題】免疫および非免疫ベースの治療薬の生産並びに疾患診断のための新規な標的の提供。【解決手段】共刺激ファミリーメンバーと予想され、肺癌、卵巣癌および結腸癌を含む癌に差次的に発現されるVSIG1、ILDR1、LOC253012、AI216611、C1ORF32またはFXYD3抗原に対する治療抗体、並びに診断及び治療の用途を提供。また、B7共刺激を調節するため、自己免疫の治療などの関連する治療のための、これら抗体の利用。更に、免疫療法、癌治療、及び薬剤開発のための適切な標的である、VSIG1及びその変異体、FXYD3及びその変異体、ILDR1及びその変異体、LOC253012およびその変異体、AI216611及びその変異体、並びにC1ORF32及びその変異体の細胞外領域の発見。【選択図】図1