IL-1– and TNF-induced recruitment of NEMO to punctate structures is a rapid and transient event. GFP-NEMO–expressing fibroblasts were treated with IL-1 or TNF, and movies were acquired by video microscopy. Still images (at the times indicated, in seconds) after IL-1 (A) and TNF (B) stimulation are presented. These images were extracted from a single representative experiment out of 13 repeats (for IL-1 stimulation) and 9 repeats (for TNF stimulation). The graphs show the number of IL-1– (A) and TNF-induced (B) GFP-NEMO–containing spots per cell (determined as described in the Materials and methods). Each curve represents the number of spots detected in individually recorded cell. Bars, 10 µm.