PARP1 and colorectal carcinoma: To characterize the phenotype of CSCs after the overexpression of PARP-1, and before and after treatments, we analyzed the percentage of cells with a high expression of CD44 and CD326 (CD44highCD326high) and with a high expression of CD44, CD326, and CD133 (CD44highCD326highCD133high), all of which are recognized as surface markers of the CSC subpopulation in CRC [5].