Confocal immunofluorescent analysis of HT-1080 cells treated with either U0126 (MEK1/2 Inhibitor) #9903 (top, left/right), or PDBu (Phorbol 12,13-Dibutyrate) #12808 (bottom, left/right) using p44/42 MAPK (Erk1/2) (137F5) (Alexa Fluor® 647 Conjugate) Rabbit mAb (red). Blue pseudocolor = Hoechst 33342 #4082.