EZH2 and B-cell chronic lymphocytic leukemia: Analysis of serial samples obtained over a period spanning 2-7 years from 6 progressive U-CLL cases (Supplemental Table 3), revealed that EZH2 mRNA levels significantly increased at disease progression (FD = 1.6, p < 0.05) and relapse (FD = 2, p < 0.05) compared to diagnosis, consistent with the notion that disease aggressiveness is correlated with high EZH2 levels (Figure 1C, 1D).