On the cover: Significant IgA production is shown in cryosections from the rolled up small intestine of a wild-type mouse. The intestine contains many IgA-positive cells (green) and a single isolated lymphoid follicle cluster brightly stained for IgM+ cells (red). Bergqvist, P., E. Gärdby, A. Stensson, M. Bemark, and N. Y. Lycke. 2006. Gut IgA class switch recombination in the absence of CD40 does not occur in the lamina propria and is independent of germinal centers. J. Immunol. 177: 7772–7783.