Genomic and expression analyses of CDKN1B in human T-PLL samples. (A) Sequence analysis of CDKN1B exon 1 amplified from the TP72 DNA leukemic sample. This patient carried a c.118G>T/p.E40X nonsense mutation in one allele. Chromatogram is shown on the bottom panel; sequence is indicated above. K=G+T. Putative translation of both alleles is shown on the upper panel using the single letter code. X indicates the stop codon. (B) Expression analysis of 20 T-PLL cases and of CD3⁺ T cells from 5 healthy individuals. Means are indicated as empty squares; plus or minus SDs are indicated as lines. An asterisk indicates the significance at P < 10⁻³ of the between-group analysis (bracket) determined by Student t test. CD3⁺ indicates control CD3⁺ T cells; 12p^DEL, patients with 12p13 deletion; and 12p^WT, patients without evidence of 12p13 genomic alteration. CDKN1B relative expression is expressed as 2^{− ΔΔCt} in which ΔCt = Ct_CDKN1B − Ct_GUSB; ΔΔCt = ΔCt_sample − ΔCt_calibrator.