Likewise, Xiao et al. utilized 2-D difference gel electrophoresis and mass spectroscopy to identify 16 candidate protein biomarkers to discriminate lung cancer patients from healthy control patients, and 3 of these (haptoglobin hp2 (HP), α2-glycoprotein (AZGP1), and human calprotectin) showed reliable discriminatory power, with 88.5% sensitivity and 92.3% specificity with an AUC of 0.90 [46]. The gene discussed is HP; the disease is lung cancer.