Figure 4

Effect of time on gene expression (Microarray study). A. Time effect within one month: Day 14 vs. Day 28. Each dot corresponds to a probe set. The differences on the vertical axis and the means on the horizontal axis were not computed from the normalized expression values but from the effects (β _{time, p}) determined by the linear model (see Methods), time being either Day 14 or Day 28; Day 1 was defined as baseline. The model used log2 values for the gene signal intensities. A robust local linear fit of the data is represented as a black line.