Effect of transient expression of exogenous RUNX1 on expression of endogenous RUNX1 in 293T cells. (A) Western blot analysis of total RUNX1 protein in 293T cells transiently transfected with FLAG epitope-tagged RUNX1 expression vector (RUNX1-FLAG), over a 10-day time course. Immunostaining performed with antibodies directed against RUNX1, FLAG tag, and β-actin control. (B) Agarose gel electrophoresis showing semiquantitative RT-PCR measurement of RUNX1-FLAG transcript, corresponding to the transfection performed in panel A. UT, untransfected. (C) Average fold change of RUNX1 transcript in 293T cells transiently transfected with RUNX1-FLAG plasmid, relative to untransfected control, as measured by qRT-PCR. Error bars show standard deviation of 3 repetitions.