To determine whether in a subpopulation of CLL cells STAT3 is both phosphorylated and acetylated, we immunoprecipitated CLL-cell protein with anti-serine pSTAT3 antibodies and found that acetyl-STAT3 was readily detected in the serine pSTAT3 immunoprecipitate (Figure 2B), suggesting that in a subpopulation of CLL cells STAT3 is both serine-phosphorylated and lysine-acetylated. The gene discussed is STAT3; the disease is B-cell chronic lymphocytic leukemia.