a. C/EBPβ protein was measured in control or shCEBP-expressing cells via Western blot. shCEBP_1 had 64% reduced levels of activating C/EBPβ isoforms (LAP1&2) while shCEBP_2 had 59% reduced activating C/EBPβ isoforms, n=3. b. OPN, IL-6, and IL-8 mRNA expression were decreased in senescent shCEBP_1 and shCEBP_2 BJs relative to control (shLUC), n=3, *p<0.05. c. Senescence-associated β-galactosidase (SA-βgal) staining was used to measure senescence induction in BJ fibroblasts expressing one of two independent shRNAs targeting C/EBPβ (shCEBP_1, shCEBP_2) or a control hairpin (shLUC) and treated with bleomycin (Bleo, 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 d. Cell proliferation over four days in non-senescent or bleomycin-treated fibroblasts was not affected by depletion of C/EBPβ, n=3, *p<0.05. e. Expression of OPN and IL-6 are significantly reduced in senescent cells expressing dominant negative C/EBPβ (DN-CEBP) relative to empty vector control, n=4, *p<0.05 f. SA-βgal staining indicates no change in senescence induction following bleomycin treatment in vector compared to DN-CEBP fibroblasts, n=3, n.s.=non-significant, *p<0.05, ***p<0.001. Scale bar=100 μm.