Dissected tissues were digested in 200 μL of 50 mmol/L Tris-HCl (pH 8.0) containing 1% sodium dodecyl sulfate-proteinase K and incubated at 42°C for 12 to 24 h. The digested products were purified by treatment with phenol-chloroform. DNA was precipitated using the ethanol precipitation method in the presence of glycogen. For microsatellite analysis, 19 microsatellite markers on chromosome 5q (including D5S118, D5S107, D5S644, D5S409, D5S346, D5S421, D5S404, FBN 2, IRF-1, IL-9, D5S414, D5S178, D5S210, D5S209, D5S820, D5S400, D5S625, D5S429, and D5S498) were obtained (Research Genetics; Huntsville, AL). One of the primers for each marker was end-labeled with [γ-32P] ATP (3,000Ci/mmol; Buckinghamshire, UK) and T4 DNA polynucleotide kinase (New England Biolabs; Beverly, MA). Polymerase chain reactions (PCRs) were carried out in a 12.5-μL volume of a solution containing 20 ng of genomic DNA, 1% dimethylsulfoxide, 200 μmol/L deoxynucleoside triphosphate, 1.5 mmol/L MgCl2, 0.4 μmol/L PCR primers, including 0.1 μmol/L γ-32P-labeled primer, and 0.5 U of Taq DNA polymerase (GIBCO-BRL; Gaithersburg, MD). DNA was amplified for 35 cycles at 95°C for 30 s, 52 to 60°C for 60 s, and 70°C for 60 s in a temperature cycler (Hybaid; Omnigene; Woodbridge, NJ) in 500-μL plastic tubes, followed by a 5-min extension at 70°C. The PCR products were separated on a 6% polyacrylamide-urea-formamide gel, which was then autoradiographed. LOH was defined as a > 50% reduction of the intensity by visual inspection in either of the two alleles compared with those in normal control panels. Shifted bands were determined by the appearance of clear novel alleles that were not observed in normal tissue control panels.