Scatter plot of entire gene set considered expressed (p values = 0.05) in the microarray analysis. The position of each dot on the scatter plot corresponds to the normalized average signal intensity (log scale) of a single gene. The normalized average signal intensity under the DDC overexpression conditions are shown on the x and y axes (controls = no DDC overexpression and DDC = DDC overexpression). The middle line indicates values that represent a DDC/controls ratio of 1.0 (similar levels of expression in both cell lines). The outer lines represent a DDC/controls ratio of 2.0 (upper line; 2-fold greater expression in DDC compared to controls) and of 0.5 (lower line; 2-fold greater expression in controls compared to DDC).