(A) Comparison of relative peak height values: control/cell lines. Comparisons of relative probe peak heights between cancer cell lines in dark grey, and control, in yellow. FHIT exon specific probes are marked FHIT E1, E2...and WWOX exon probes: WWOX E1, E2. Internal controls probes are labeled according to their chromosomal location. Top, cell line SNO showing a homozygous deletion of FHIT exon 5 with both exon 5 probes. The second and third internal control probes, on 10p and 9q, appeared increased in copy number in SNO. They were not used to normalize data when ratios were derived from absolute peak height values. Middle, no significant deletion nor amplification in either FHIT or WWOX was seen in WHCO3. (B) Absolute peak height values, comparison control/cell line WHCO5. Bottom, comparison of absolute probe peak heights between WHCO5 in dark grey, and control, in yellow. FHIT exons 4 and 5 were present in half copy number. Controls probes on chromosome 16 were consistent with the external control.