title: B cell activation: three steps and their variations.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D002453:Cell Cycle; D004261:DNA Replication; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008222:Lymphokines / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000949:Histocompatibility Antigens Class II; D008222:Lymphokines