Figure 1.

(a) Original pan-cytokeratin-stained image of an OTSCC lesion. Bar = 1 mm. (b) Tissue-array apparatus used to collect a core biopsy of 3 mm in diameter from the deepest invasion front (see Plate S1). (c) Preparation of serial sections (4 μm thick) from the core specimen using a rotary microtome. The serial sections were conveyed via continuous laminar water flow directly from the knife edge to the heated water bath. (d) Three rows of 9 sections were mounted on each glass slide for immunostaining with Ki67 and CK cocktail. (e) All histological images were digitized using virtual microscopy.