Figure 4. Differential expression of stemness markers between OVCAR-3 and OV3R-PTX-B4 cells. (A) Detection of CD44, CD133, NANOG, and OCT4 positive cell population in OVCAR-3 (blue) and OV3R-PTX-B4 cells (red) by flow cytometry. (B) Expression of CD44, CD133, NANOG, and OCT4 proteins in OVCAR-3 and OV3R-PTX-B4 cells detected by Western blot. Upper panel, representative images of blotting; low panel, semi-quantitative analysis of the relative optical density of protein bands in the upper panel. β-tubulin and GAPDH were used as loading controls. n = 3; *, P < 0.05; **, P < 0.01.