Fig. 6. Further analysis of p21-induced ROS. (A) Immunostaining with p21 antibody of EJp21 cells in the presence of tet for 2 days (Control) and after 2 (2d) or 5 (5d) days of p21 induction by tet removal. Cells were photographed using a Nikon Microphot-FXA microscope (400×). (B) PIG3 is induced by p21 or mutant p21 but not p16. Northern blot analysis of p21 and PIG3 RNA levels in EJp21 cells in the presence of tetracycline for 1 or 3 days (+1d and +3d) and after 1 or 3 days of induction (–1d and –3d), compared with levels in EJp16 in the same conditions. Exo, induced p21; endo, endogenous p21.