We studied mechanisms of cell-to-cell fusion (Sottile et al. Cell Reports 2017) and ploidy maintenance (Frade et al. Science Advances 2019). We showed that bone marrow (BM) cells fuse with retinal neurons and Muller glia cells in degenerated mouse retinas. The in-vivo formed hybrids undergo reprogramming and regenerate neurons in drug-induced and genetic models of retinal degeneration (Sanges et al. Cell Reports 2013; J. of Clinical Investigation 2016; Pesaresi et al. eBiomedicine 2018). Furthermore, other key discoveries showed that BM-derived hybrids can functionally rescue dopaminergic neurons in two Parkinson’s disease mouse models (Altarche-Xifro et al., eBiomedicine 2016) and regenerate mouse liver after hepatectomy (Pedone et al., Cell Reports 2017). Finally, we recently identified the released chemokines from damaged human and mouse retina and in turn we defined the chemokine-receptor interactions to enhance migration and integration of transplanted cells into the mouse retina (Pesaresi et al. Molecular Therapy, 2020).