CD44 immunocytochemistry. Above: two of the six original ESCC lines (YES-1 and YES-2) and their curcumin-surviving lines (YES-1S and YES-2S) stained with anti-CD44. Below: histograms showing the high-staining subpopulations in the original cell lines (peak marked by asterisk) which is diminished in the surviving lines. Scale bar =100 μm. There were significant high-staining cell numbers within all original and surviving lines. The mean intensity of high-staining cells was 446.47 ± 31.21, 438.96 ± 55.38, 463.79 ± 50.66, and 470.20 ± 53.77 for YES-1, YES-2, YES-1S, and YES-2S, respectively (F=228, p<0.0001).