CNAs and unbalanced breakpoints in six ESCC cell lines detected by array-CGH. Gains and amplifications are presented as lines on the right side of the chromosomes, while the lines for losses and deletions are on the left side. Unbalanced breakpoints are at the boundaries of CNAs. Numbers on top of the lines are indicated as the cell lines. 30: KYSE30, 150: KYSE150, 180: KYSE180, 450: KYSE450, 510: KYSE510, 2: YES2.