Loss of heterozygosity on chromosome arm 1p in CML. (A) LOH was detected on D1S468 in CML no. 11. Heterozygosity was retained at D1S243 and D1S199. (B) Allelic loss was observed at D1S228, whereas heterozygosity was retained atD1S243 and D1S507 (CML no. 24). (C) LOH was found atD1S2667, whereas heterozygosity was retained at D1S508and D1S199 (CML no. 1). The locus symbol is shown on the top. Arrow indicates allele lost. B, blast crisis; C, chronic phase.