A method of diagnosing
pancreatic ductal adenocarcinoma (PDAC) comprising detecting an
autoantibody of GAGE1 (G
antigen 1, GAGE4) and an
autoantibody of ACVR2B (
activin A receptor type 2B). Also claimed is a method of diagnosing PDAC comprising detecting an
antibody which binds to LEMD1, MAGEB1, PAGE1, TSGA10, BAGE4, AURKA, MAGEA10, PLEKHA5, PLK4, XAGE3Av1. The autoantibodies may be IgA and / or IgG antibodies. The method may comprise contacting a sample with GAGE1 and ACVR2B antigens and detecting the binding of antibodies to the antigens. The levels of antibodies may be quantified and compared to
healthy subjects or those with chronic
pancreatitis. The antigens may be bound to a support, such as a bead, membrane, slide, plate, well, filter, or
dipstick. The method may comprise detecting GAGE1, ACVR2B and other additional antigens. Also claimed is an
antigen complex comprising a
biotin carboxyl
carrier protein (BCCP)-tagged
antigen bound to a support, wherein the antigen is GAGE1, and wherein the support is coated with
streptavidin, for use in the method. A kit comprising GAGE1 and another antigen. Also claimed is a computer implemented method of diagnosing PDAC comprising comparing data comprising the number of antibodies detected to reference data and displaying a diagnosis.