Figure 5: Cellular expression of p70. Panel (a)—p70 is not detected in vascular smooth muscle cells, HEK293, or Cos-7 cells after growth in serum-free medium. vSMCs, HEK293, and COS7 cells were grown either in the presence of serum (DMEM plus serum) or in serum-free medium (ExCell) and cellular extracts analyzed by western blotting using p70 antibody. FBS (extreme right lane) served as a positive control. Panel (b)—detection of p70 and BSA in vascular smooth muscle cells. Cell-associated albumin can be detected with p70 antibodies upon albumin addition for 30 min. Similar results were seen in 2 independent experiments.