**5. Conclusion**

We have mapped the mouse *Hcs7* liver cancer modifier to a 3.3 Mb region on distal Chromosome 1 that carries 44 genes, of which many are involved in responding to immune stimuli. This region corresponds to human chromosome 1q22-23.1, which is amplified in most hepatocellular carcinomas. *Ifi202b* is a strong candidate gene for the *Hcs7* modifier. Further study of the effect of its overexpression or disruption *in vivo* on short-term proliferation or apoptosis and long-term hepatocarcinogenesis will help establish whether its possible functional equivalent on human chromosome 1q is a worthy target for pharmacological intervention.
