highly significantP < 0.001
Comparing the log 2 fold changes in gene expression upon RA treatment with those upon 5-aza-dC treatment reveals a highly significant ( P < 0.001) positive correlation (R = 0.76, red), which is even retained when comparing those genes significantly regulated in only one of the two conditions (R = 0.72, 5-aza-dC, brown; R = 0.57, RA, green; Figure 1 C, left panel).