To determine the cause of the reduced p27 expression level in the tumors of this patient, we extracted DNA from tumor and adjacent normal cells and performed LOH analysis by amplifying three microsatellite markers flanking the p27 locus (at position 12,76 Mb on chromosome 12p): D12S391 (12,34 Mb), D12S358 (12,53 Mb) and D12S1580 (13,23 Mb). This evidence concerns the gene CDKN1B and neoplasm.