Dr Gallego's expertise has focused on pathways involved in mammary morphogenesis, differentiation and tumourigenesis. A long-term interest was the study of the mammary phenotype of mutant mice that do not express Hedgehog proteins, performing a pioneering study of the role of Hedgehog signalling in mammary gland morphogenesis. In the same vein, the study continued with the generation of transgenic models of the Shh overexpression in the mammary gland, uncovering the paracrine nature of Hedgehog signalling in the epithelial compartment of the mammary gland, where a subset of basal cells exhibiting primary cilia and expressing mammary progenitor cell markers expand in response to a Shh secretion by the luminal epithelium. In recent years, Dr Gallego has also been interested in the involvement of signalling pathways in the aetiology of multiple sclerosis, collaborating with Dr Ballester's laboratory in an experimental autoimmune encephalomyelitis (EAE) project. The report they now present brings together Dr Gallego's interest and expertise in Hedgehog signalling and Dr Sara Ballester's expertise in EAE.