STAT1 and B-cell chronic lymphocytic leukemia: Among these molecules, STAT1 (p = 0.01) (Figure 3-IB), NFATC2 (p = 0.04) (Figure 3-IC), and c-Fos (p = 0.03) (Figure 3-ID) were found to be significantly overexpressed in low CTLA4 CLL cells.