viruses with mutations in both copies of the leukemia virus factor a ( lva ) site , leukemia virus factor c ( lvc ) site , or in just the promoter proximal copy of the glucocorticoid response element ( gre ) had a latent period of disease onset and disease specificity indistinguishable from that of the wild-type moloney virus .
C0086860
proximal
C0600508
response element