STAT3 and B-cell chronic lymphocytic leukemia: We found significant higher levels of both STAT3 (1.13 ± 0.11 vs. 0.61 ± 0.09; Mann–Whitney test, p = 0.0098, Figure 1A,B) and JAK2 (0.76 ± 0.06 vs. 0.44 ± 0.11, Mann–Whitney test, p = 0.0101, Figure 1C,D) proteins in CLL cells as compared to normal B lymphocytes.