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Composite confocal overlay series of images demonstrating that type I CD20 antibody rituximab binds differently to lymphoma cells as compared with the type II CD20 antibody GA101. Each pair of images shows a Ramos cell exposed to GA101 (left) and rituximab (right), along with a lipid raft marker. The green panels show the distribution of lipid rafts (labeled with CTB-Alexa 488 cholera toxin subunit B, which binds to the membrane ganglioside GMI in lipid rafts) and the red panels the distribution of the CD20 antibodies (labeled with Cy3), and the bottom panels in each set show the overlay of the green and red images. The overlays confirm that the binding of the type I antibody rituximab to CD20 results in accumulation of CD20 clusters in lipid rafts as shown by colocalization with CTB-Alexa 488 (yellow fluorescence), whereas CD20 molecules do not redistribute to lipid rafts upon binding of the type II CD20 antibody GA101 and do not colocalize with CTB-Alexa 488. To illustrate the different localizations of rituximab and GA101, 3 different image-processing algorithms from Jasc Paint Shop Pro (Version 9.01) were applied to the original confocal pictures shown on the top left (Figure 2C, Mössner et al on page 4397) and are shown on the top right, and bottom left and right. This composite cover was prepared by Christian Klein with help from Claudia Kirstenpfad. See the article by Mössner et al on page 4393.