To assess whether the cellular identity of AD-iN cells requires continuous transgene expression, we withdrew doxycycline at various timepoints after infection and characterized the iN cells at 4 WPI. 14 d of doxycycline treatment was sufficient to generate stable neuronal cells in vitro (Supplementary Fig. 7). In order to evaluate the cell-fate stability of iN cells more rigorously, we collected EGFP-labeled AD-iN cells at day 14 and injected them into the subventricular zone and cerebral cortex of newborn severe combined immunodeficient (SCID) mice.
