To calculate the depletion of cytoplasmic fluorescent proteins,fluorescence intensities in a cytoplasmic area were determined before and 30 minutes after receptor stimulation (αTNF-R2). All measurements were corrected for bleaching effects, which were obtained by analyses of nonstimulated cells. Bleaching effects in all experiments were between 3 and 12% with an average of 7.3%. Depletion of TRAF2-GFP was determined after transfection of a 1:1 mixture of a TRAF2-GFP expression plasmid and empty vector, and depletion of cIAP1/2-GFP was determined after transfection with a 1:1 mixture of expression plasmids encoding TRAF2 and cIAP1/2-GFP.