In this report, we determine whether genes identified in a previously reported cDNA microarray investigation of childhood acute lymphoblastic leukaemia (ALL) diagnostic bone marrow have the same distinguishing power in an independently derived cDNA microarray dataset from an equivalent but distinct patient cohort. Genes previously reported as discriminatory, generally were unable to distinguish ALL lymphocyte lineages, the presence of the Tel-AML1 translocation and patient risk stratification. An artificial neural network identified endoglin, which was reported in the initial study as a potential lineage marker, was actually better at identifying ALL patients with poor outcome.