Dendritic cells are professional antigen presenting cells and central for establishing and maintaining immunity and immunological tolerance. They develop from hematopoietic stem cells through successive steps of lineage commitment and differentiation. Dendritic cell development and function are regulated by specific cytokines, including transforming growth factor type beta1 (TGF-beta1). Our previous work demonstrated the importance of TGF-beta1 signaling for dendritic cell development and subset specification. Here, we used genome-wide gene expression profiling with DNA microarrays to investigate the activity of TGF-beta1 on gene expression in dendritic cell development. This study identified specific gene categories induced by TGF-beta1 with an impact on dendritic cell biology.