Our main interest in the laboratory aimed at unraveling how stem cells in the brain are guided to different fates and stimulated to proliferate by extracellular signals, focusing in particular in the Hedgehog morphogen (Hh) and its crosstalk with other signaling pathways such as the Epidermal Growth factor (EGF) pathway. Experiments are carried out in the mouse or chicken brain, though we have established the culture of neural stem cells as an appropriate and controlled system for the analysis of Hh function. There is much interest from the biomedical community in this work because this extracellular molecule holds great promise for the manipulation of cells in culture to either proliferate or adopt neural differentiation pathways. The action of the Hh signal is complex and is mediated by a host of related transcription factors that activate context-specific targets. For a full understanding of how to use Hh as a cue for cell manipulation, it is crucial to unravel the network of genes that are activated by the signal. Our laboratory has embarked on a project that characterizes the Hh pathway by taking an unbiased look at the genomic response induced by its activity using both zebrafish and mouse embryonic models and reporter cell lines for Hh signaling. Deciphering how the graded Hh signals are converted to discrete cell-fate decisions also holds therapeutic potential in the context of tissue engineering of other stem cell populations. Periodontitis is one of the most prevalent infectious diseases and since the main goal of periodontal therapy is regeneration, we have recently become interested in characterizing the potential role of Hh signalling in the renerative process of human periodontal ligament tissues.