Confocal images of propidium iodide (PI) stained suspicious circulating elements obtained from SQCLC patients.

<p>The upper part of the figure shows a PI stained SCE with multiple green signals referring to multiple copies of <i>FGFR1</i> gene (scale bar = 5 μm); the middle part shows a PI stained nucleus with EpCAM expression (scale bar = 5 μm) and the bottom part a PI stained nucleus with vimentin expression (scale bar = 10 μm) associated with two small leukocytes showing a faint cytoplasmic fluorescence.