Overall expression profile of normal gastric mucosa, EGC and AGC. Left: two-way hierarchical clustering based on 954 probe sets that varied the most across the three classes of normal (NOR), EGC and AGC samples with Spearman correlation similarity measure. Right: the expression values of the two major clusters of genes are also shown as box plots, displaying the distribution of relative gene expressions in each sample for the selected gene list. Each box extends from the 25th to the 75th percentiles; the solid line within each box represents the median. The whiskers below and above each box plot extend to the 1.5x of the interquartile range (75th–25th percentile). Sample code: cyan, Normal; blue, AGC; red, EGC. Topology code: black, cardias; grey, antrum; cyan, fundus; violet, body. Grade code: black, G3; dark gray, G2; light gray, G1; white, not applicable (NOR).