Fig. 2.

Results of human antibody arrays to measure serum proteins in ESCC patients.

Volcano plots of candidate protein expression in ESCC and normal control from the Human Antibody Array AAH-BLG-1000 (a) and the Human Cytokine Array AAH-CYT-G4000 (b). X-axis: log2 ratio of protein expression levels (fold change) between normal control and ESCC. Y-axis: the p value (−log10 transformed) of proteins. The vertical dotted lines correspond to 1·5-fold up and down, respectively, and the horizontal dotted lines represent a p value of 0·05. Hierarchical clustering results of serum proteins displaying higher levels in patients with ESCC than normal controls (fold change > 1·5) were measured by the Human Antibody Array AAH-BLG-1000 (c) and the Human Cytokine Array AAH-CYT-G4000 (d). Each row represents an individual protein, while each column indicates an individual serum sample. The colour scale bar is on the right of the heat map, with the highest and lowest values in red and blue, respectively. Representative results of IGFBP1 from AAH-CYT-G4000 were also shown (e). N1 to N4 are normal controls, and C1 to C4 are ESCC patients. ESCC, oesophageal squamous cell carcinoma.