Ikaros, Aiolos and Helios encode zinc finger transcription factors that are important regulators of lymphoid development and differentiation. These proteins are involved in the control of gene expression and when associated with nuclear complexes, participate in nucleosome remodeling. Because differential splicing produces multiple protein isoforms with potentially different functions, the Ikaros protein family provides a useful model for the study of whether post-transcriptional modifications are involved in tumoral transformation. Several reports reinforce the hypothesis that Ikaros, Aiolos and Helios expression is deregulated in human leukaemias. The direct involvement of aberrant protein expression of Ikaros family members in human haematological malignancies is discussed.