After infection with a recombinant adenovirus coding for luciferase and ovalbumin (OVA), which results in hepatocyte infection that can be monitored by in vivo bioluminescence measurement21, in vivo activation of ovalbumin-specific OT-ICX3CR1-GFP T cells was observed at 2 days post infection (d.p.i.)as demonstrated by increased CD44 expression. The gene discussed is CD44; the disease is infection.