UGT2B17 and B-cell chronic lymphocytic leukemia: Enzymatic assays with PGE2 further established that primary CLL samples and cell lines expressing high UGT2B17 levels produced significant amounts of PGE2-G1 and PGE2-G2 derivatives whereas they were not detected in those expressing low UGT2B17 levels in CLL patients (Figure 5D).