Identification of serum C-reactive protein-bound serum amyloid A (CRP-SAA) complexes in serum samples from lung cancer patients. a Sodium dodecyl sulfate–polyacrylamide gelelectrophoresis (SDS-PAGE) and mass spectrometry (MS) of serum samples from healthy controls and lung cancer patients. The red frame indicates the discrepant bands. b Analysis of discriminative masses between normal and cancer serum samples through two-dimensional electrophoresis (2-DE) and MS. The red arrows indicate the discrepant masses corresponding to SAA1/SAA2 proteins.