a plasmid probe located at the centromere (cen) of chromosome 7. The specificity and location of the probes were confirmed by FISH on normal metaphases before hybridization on the TMAs. When clones were available, and in order to increase the signal, two or three BAC clones around the test gene or EST were hybridized together. Control FISH experiments on normal interphase nuclei were performed beforehand in order to ensure a unique signal when two BAC clones were hybridized together. BAC clones on 13q were purchased from the BACPAC Resources Center (Children's Hospital Oakland Research Institute, CHORI). All other clones were generously provided by Dr. Rocchi.