a. Senescence-associated β-galactosidase (SA-βgal) staining was used to measure senescence induction in bleomycin-treated BJ fibroblasts expressing one of two independent shRNAs targeting c-Myb (shMYB_1, shMYB_2) or a control hairpin (shLUC; left). There is no significant difference in percent SA-βgal+ cells among any of the hairpins (right), n=3, n.s.=non-significant, *p<0.05. Scale bar=100 μm b. c-Myb, C/EBPβ and p65 protein levels were measured in control or shMYB-expressing cells via Western blot. shMYB_1 had 63% c-MYB while shMYB_2 had 55% c-Myb relative to control, n=3. c. OPN, IL-6, and IL-8 mRNA expression were decreased in senescent shMYB_1 and shMYB_2 BJs relative to control (shLUC), n=3, *p<0.05. d. Cell proliferation over four days in non-senescent or bleomycin-treated fibroblasts was not affected by depletion of c-Myb, n=3 *p<0.05, ***p<0.001.