GpIX expression in HUVECs, CHRF-288, and HEL cells. Genomic DNA or RT-RNA from HUVECs, CHRF-288, and HEL cells and from hepatoma 3B cells was amplified by PCR, as described in Materials and Methods, using GpIX primers that span the 108-bp intron in the GpIX 5′ untranslated region. A 100-bp marker ladder (M) is shown on the left.