definiens: shall mean(rodents, --that are genetically modified 0 as to contain human i immunoglobulin variable gene ejements which are capable of i undergoing rearrangement and o~ producing immunoglobulin I molecules or antibodies contaiHing human variable gene elements, I I whether heterozygous or homozy ~ us for such modification and whether first generation or prlPeny, including without limitation, ( i ) rodents which pssess human immunoglobulin heavy ~ i chain gene elements that are c pable of undergoing rearrangement for the production of function ~ immunoglobulin molecules ; and ( ii ) rodents which possess hum'f immunoglobulin light chain gene I elements that are capable of ul ~ ergoing rearrangement for the production of functional immUn(~lObUlin molecules ; and ( iii ) I rodents which possess human imn ~ nOglObulin heavy chain gene I elements and human immUnOglObul Wn light chain gene elements, I wherein each of the heavy and l~9ht chain gene elements are I capable of functional undergoing rearrange ~ent for the production of immunoglobulin molec ' les . r i 15- F:\A\22960\OOOI\GENP\LIC·CR9 .SCF I ! ! I, I i