A dominant-negative form of Stat3 did not inhibit IL-6–induced repression of BCL2 mRNA expression. 1A9-M cells transfected with either a control vector (1A9-M/pCAGGS clone 1 and 2) or a pCAGGS-Neo-HA-Stat3D plasmid (1A9-M/ST3D clone 1 and 2) were cultured with or without 20 ng/mL IL-6 for 24 hours. Total RNAs were isolated and subjected to Northern blot analysis using cDNAs of BCL2 and β-actin as probes.