PROM1 and malignant colon neoplasm: Based on a study by O'Brien et al. [82], which identified CD133 as a marker for cancer stem cells (CSC) in CRC, Yanhong Deng et al. found that membrane CD133 expression in HT29 (COX-2 positive) and DLD1 (COX-2 negative), two human colon cancer cell lines were downregulated on celecoxib treatment, which was confirmed by Western blotting and qPCR.