a. Western blot showing total c-Myb expression in the non-senescent and senescent cells used for ChIP. b. Chromatin immunoprecipitation was used to measure c-Myb binding to the OPN, IL-6, and IL-8 promoters in 293T cells expressing exogenous c-Myb cDNA. C-Myb significantly binds to all three endogenous promoters relative to IgG control, representative experiment, n=3, n.s.=non-significant, *p<0.05. “nspc.” indicates pulldown with c-Myb antibody at a distal site. c. c-Myb binds the OPN190 promoter reporter construct relative to IgG control. Mutation of the c-Myb binding site (mutations indicated below) eliminates binding to the OPN190 construct, n=3, n.s.=non-significant, *p<0.05. d. Luciferase activity is increased in senescent BJ fibroblasts expressing the WT OPN190 construct relative to non-senescent cells, but not in fibroblasts expressing the mutant c-Myb binding site OPN190 construct (OPN190MUT MBS), n=4, n.s.=non-significant, *p<0.05.