Interestingly, oval cells, known to express CXCR4 as well, have been reported to migrate to the liver along a CXCL12 gradient, established by injured hepatocytes, inducing oval-cell-aided liver regeneration in hepatitis (Hatch et al, 2002; Mavier et al, 2004). This evidence concerns the gene CXCL12 and hepatitis A virus infection.