Cellular aspects on the phylogeny of immunity.
D000818:Animals; D005075:Biological Evolution; D004848:Epithelium / Q000276:immunology; D006801:Humans; D007109:Immunity; D007448:Invertebrates / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D014714:Vertebrates / Q000276:immunology