In addition, after marked basal cell injury (induced by a Krt5–diphtheria toxin system) secretory cells are capable of dedifferentiating and repopulating the basal cell population with similar self-renewal rates as ‘normal’ basal cells, with these secretory cell-derived basal cells also able to promote epithelial repair and give rise to all three main epithelial cell types after influenza infection [14]. The gene discussed is KRT5; the disease is influenza.