Visualization of FEN1. Top: UCSC Genome Browser view of FEN1 probe alignments alongside AceView transcripts. The four misbehaving probes are outlined in green. Bottom Left: Heatmap visualization of the genes according to pairwise Euclidean distance. Probes 1–16 are Affymetrix, 17 is Agilent, and 18 is Codelink. Probes 5–8 (green outline) are distant from the rest of the probes in the set, creating a white cross in the symmetric matrix. The rest of the probes are all in high agreement with each other with short distances between expression vectors. Bottom Right: Log2 signal intensity of the replicates. The signal intensities of the misbehaving probes, outlined in green, do not show the same high degree of separability between the control and treatment groups that is exhibited by the rest of the probes. The signal intensity graph confirms that these probes behave differently and should form their own cluster, as found in the heatmap.