Haematopoiesis – the process by which pluripotent haematopoietic stem cells choose to become lymphocytes, myeloid cells, red blood cells or platelets – has long been a useful model to study cellular commitment and differentiation. Each cell type is defined by lineage-specific patterns of gene expression. The DNA binding protein Ikaros is an important regulator of haematopoiesis and recent work promises to shed light on how Ikaros itself is regulated.