It has been proposed that their expression is controlled by the non-clonal , or innate , component of immunity that preceded in evolution the development of an adaptive immune system in vertebrates .
it has been proposed that their expression is controlled by the non-clonal , or innate , component of immunity that preceded in evolution the development of an adaptive immune system in vertebrates .
O O O O O O O O O O O O O O O O O O O O O O O O O O O B-body_part I-body_part I-body_part O B-multi_cell O