Figure 1. Chromosomal location of the Affymetrix exon array probesets within EGFR, KRAS and VEGFA.

The red ticks show the exonic probesets, the gray ticks display the non-exonic probesets (intronic, intergenic and unreliable). In EGFR, KRAS and VEGFA, a total of 51 of 451, 13 of 262 and 25 of 26 exonic probesets were measured respectively. All other probesets were situated outside of exons, i.e. intronic, intergenic or were unreliable.