This report presents the history of the involvement of the Department of Cytology in studies of different aspects of regeneration. It can be divided into two major phases; the first focused on the regeneration of Turbellarians and the second on the regeneration of rat skeletal muscles including the differentiation of satellite cells in vitro. Regeneration of Turbellarians was investigated both at the cellular and molecular levels including the role of the protein kinase C (PKC) in this process. Studies on skeletal muscle regeneration initially focused on factors involved in regulation of signal transduction pathways. Next, we explored the influence of growth factors on the modulation of the regeneration process. Another important aspect of our studies was investigating of the distribution and function of different proteins involved in adhesion and fusion of myoblasts. Finally, we are also conducting research on the role of stem cells from other tissues in the regeneration of skeletal muscle.