The simultaneous binding of two antibodies to the same antigen (antibodies synergy or co-cooperativity) that elicit complement-mediated bactericidal activity is visualized with a model of a complex between Neisseria meningitides factor H binging protein (red cartoon) and monoclonal antibodies 12C1 (blue surface) and JAR5 (green surface). Monoclonal antibodies are schematically depicted with bars (colored light brown and yellow for heavy and light chains, respectively) in the background. Please see pp. 4699–4713 for more information. Picture generated and provided by Enrico Malito.