Having established the specificity of the GFP-lacI binding by co-localization, we examined fluorescence of live cells by time-lapse microscopy following transfection with pSV2-dhfr-8.32 and infection with vGFP-lacI. Weak GFP fluorescence was detected at about 5.5 h after infection (not shown) and was largely over the nucleus, reflecting the targeting due to the NLS. The gene discussed is TFPI; the disease is infection.