Megakaryoblastic specific genes. Semi-quantitative RT-PCR analysis in 3 T-cell (T, 1-3), 3 B-cell (B, 4-7), 1 myeloid (M, 8), 3 erythroid (E, 8-10) and 3 megakaryoblastic leukaemias (Mk, 11-13). RT-PCRs have been performed in quadruplicate for each sample. Two out of 4 RT-PCR runs are shown for the leukaemic samples (lane a: 25 PCR cycles; lane b: 28 PCR cycles) and 1 out of 4 are shown for the β-actin internal control (lane c). The histograms represent the quantification of the density of the bands relative to the β-actin sample including all RT-PCR runs for each type of leukaemia (T, B, M, E, Mk).