Isabel Guerrero is the Principal investigator at the CBMSO since 1989. Currently, she directs a competitive group in the CBMSO using Drosophila melanogaster as a model system because it has unique tools for in vivo and in vitro functional studies. We focus our studies on the mechanisms of long-range communication during developmental to build a tissue. One important question in developmental biology is how the morphogenetic gradients are formed to establish different cell fates during development. During the last years, we have been characterizing the mechanisms of Hedgehog (Hh) gradient formation at the genetic, cellular, and molecular level using the wing imaginal disc and the abdominal histoblasts of Drosophila as a model. The functional conservation of the Hh pathway in humans and its involvement in development, tumorogenesis and stem cell homeostasis has motivated much interest in this area of research. Our studies are at the level of genetic, cellular, biochemical, and mathematical models based on in vivo image analysis. This group has been involved in national and European projects and networks, maintaining important collaborations with national and international groups.