a, Schematic showing planes imaged in time-lapse microscopy experiments. b–d, Extracted images showing frames from Supplementary Videos 2–4. Dying GFP+Mycn+/– cells are marked with an arrowhead in the first frame of fluorescence images (top two rows) and by an asterisk in the traced panels (bottom). Wild-type cells are RFP+. e, Images from the suprabasal plane extracted from the first and last time points of Supplementary Video 1, and corresponding to the still images shown in the first and last panels of Fig. 1g. The asterisk marks the position of the dying cell 11 μm below. No new cells enter the suprabasal plane through the time course of the video, supporting the conclusion that the cell dies and is eliminated within the plane of the epidermis and not extruded to the suprabasal plane. Scale bars, 10 μm.