Figure 4.

Autoantibodies identified in lung tumors can be found in peripheral plasma complexed with antigen. Targeted antibody arrays were created by covalently linking human protein–specific antibodies to the top free autoantibody targets onto the slide surface. After hybridization with whole plasma, autoantibody–antigen complexes are detected via fluorescently labeled antihuman (A) IgG and (B) IgM secondary antibodies and quantified to compare complexed autoantibodies in plasma from malignant (n = 10) and benign (n = 10) nodule subjects (mean ± SEM; unpaired Student’s t test). BN = benign nodule; M value = log₂(red channel or green channel signal) or the expression on the log₂ scale after background correction; MN = malignant nodule.