tokens: Taken together , our studies revealed three unexpected findings which require further analysis : ( 1 ) expression of Id2 mRNA is often associated with lymphocytic transformation by HTLV-I or -II ; ( 2 ) T-cells usually express either Id2 or Id3 mRNA , but B-cells often express both simultaneously ; ( 3 ) non-dividing , normal PBL express high levels of Id2 and no Id3 mRNA ; and with the onset of cellular proliferation , levels of Id2 mRNA decrease while levels of Id3 mRNA increase , suggesting that regulation of expression of these closely related genes is disparate .