Gene expression in lung of SAD mice exposed to variable time hypoxia followed by 2 hours reoxygenation and effects of inhaled NO. On the left, the xy-scatterplots display the pair-wise comparison between gene expression levels in lungs of SAD mice control group (x axis) and that of SAD mice exposed to the indicated times of hypoxia followed by 2 hours reoxygenation (y axis). On the right, the xy-scatterplots display the pair-wise comparison between gene expression levels in lungs of SAD mice control group (x axis) and that in lungs of SAD mice exposed at the indicated times hypoxia followed by 2 hours reoxygenation breathing NO (y axis). Both x and y values represent the log₂ expression level of the same genes in the different experimental conditions (groups). The central line is the least squares regression line (Y = b + ax), and the upper and lower lines are obtained by the respective addition and subtraction to the regression line equation of the standard deviation of residuals multiplied by 1.96. The Pearson correlation value (R²) for each comparison is indicated. Spots outside the upper and lower lines represent the genes upor down-regulated with respect to SAD baseline, respectively (described in “Materials and methods”).