However, promoter sequence differences seem unlikely to underlie Theileria's ability to induce TGF-b2 over TGF-b1 transcripts, or explain the drop in TGF-b2 levels upon attenuation of the Ode vaccine line as here, both virulent and attenuated infected macrophages are of HF origin [20]. The gene discussed is TGFB2; the disease is hydrops fetalis.