LOH at TSC loci in 50 matched normal and tumor samples. a) Representative gel pictures showing LOH for markers from the TSC1 and TSC2 candidate regions. B and T denote constitutive blood and tumor DNA respectively. Arrows indicate loss or allelic imbalance of the corresponding allele in tumor DNA. b) LOH analysis of 50 matched samples at both the TSC loci. Approximate locations of microsatellite markers with respect to TSC genes are shown on the left. Tumors are grouped according to their T classification (T1–T4). Numbers represent patient numbers. Abbreviations: NI, non-informative; IN, informative; LOH, loss of heterozygosity; and MI, microsatellite instability.