Single-cell live imaging is a powerful method to investigate cell motion. Using this approach, Nanba and colleagues have elegantly demonstrated that motion can predict human epidermal keratinocyte (NHEKs) stem cell fate (Nanba et al., J. Cell Biol., 2015). Human thymus, a primary lymphoid organ, contains numerous TP63+/EpCAM+ epithelial cells (hTECs) that are cl…