The study by Vierbuchen et al. demonstrates that fibroblasts can be directly converted into functional neurons using a combination of three transcription factors: Ascl1, Brn2, and Myt11. This process, referred to as induced neuronal (iN) cell generation, is rapid and efficient, with efficiencies ranging from 1.8% to 19.5%. The iN cells generated from mouse embryonic and postnatal fibroblasts express multiple neuron-specific proteins, generate action potentials, and form functional synapses. These findings suggest that direct conversion of fibroblasts into neurons could have significant implications for studying neural development, modeling neurological diseases, and regenerative medicine. The authors also explore the kinetics and efficiency of the conversion process, as well as the molecular mechanisms underlying the conversion, including the role of transcriptional and epigenetic factors.The study by Vierbuchen et al. demonstrates that fibroblasts can be directly converted into functional neurons using a combination of three transcription factors: Ascl1, Brn2, and Myt11. This process, referred to as induced neuronal (iN) cell generation, is rapid and efficient, with efficiencies ranging from 1.8% to 19.5%. The iN cells generated from mouse embryonic and postnatal fibroblasts express multiple neuron-specific proteins, generate action potentials, and form functional synapses. These findings suggest that direct conversion of fibroblasts into neurons could have significant implications for studying neural development, modeling neurological diseases, and regenerative medicine. The authors also explore the kinetics and efficiency of the conversion process, as well as the molecular mechanisms underlying the conversion, including the role of transcriptional and epigenetic factors.