“…Similarly, comparable frequencies of Th2 cells derived from transgenic and nontransgenic mice expressed IL-4, demonstrating that the transgene had no untoward effects on Th1 or Th2 development. As anticipated from prior reports of allelic utilization of cytokine genes (Hsieh et al, 2000;Kelly and Locksley, 2000), or perhaps because of position effect variegation of the transgenic allele, the fraction of IFNg+ T cells that coexpressed Thy1.1 was approximately one-third of the total of IFNg+ Th1 cells in hemizygous transgenic mice (14.1% Thy1.1+/IFNg+ versus 50.0% total IFNg+, Figure 5, and see Figure 6). Importantly, however, essentially all of the cells that expressed the Thy1.1 reporter also expressed IFNg, validating the model for accurate identification of IFNg+ CD4 + T cells.…”