With a jumble of colors resembling abstract art, this array shows the expression of genes (horizontal rows) that are associated with different types of bone marrow progenitor cells (vertical columns). Part of a study published Aug. 31 by Nature, the image was produced from a software program called Iterative Clustering and Guide-Gene Selection, developed by researchers at Cincinnati Children’s. It gives scientists an unbiased way to identify developing cells in various intermediate states and discover new cellular intermediates. Yellow indicates highly expressed genes in particular cells, while blue indicates low or no expression. The study addresses a fundamental question of developmental biology – the nature of intermediate cell states and the regulatory gene networks that cause cell-type specification.