PROM1 and ovarian cancer: There were significantly more cases with a high expression level (>2) of CD44 and VDR in HGSC than in non-HGSC ovarian cancers (p < 0.001 and p < 0.001, respectively), while there was no difference in the distribution of the high-expression category of CD133 between HGSC and non-HGSC ovarian cancers (p = 0.467).