This near identical pattern in the effects of sorafenib on AFP production and clone formation was in sharp contrast to the moderate effect of sorafenib on the viability of HCC cells: we saw a loss of cell viability after 18h of sorafenib treatment that was consistently <10% as measured using the Trypan blue exclusion assay, in contrast to the near complete inhibitory effect of sorafenib on AFP production and clonogenic growth (Figure 1B). The gene discussed is AFP; the disease is hepatocellular carcinoma.