In addition, the immunohistochemistry analysis also indicated a high Hiwi expression in Caco-2 cells which were infected with 1 or 10 MOI Ad-Hiwi; there was a higher level of green fluorescence in the Ad-Hiwi-infected Caco-2 cells (Figure 2(c)), whereas the Ad-RFP infection caused a higher level of red fluorescence in Caco-2 cells at 1 or 10 MOI (Figure 2(c)). The gene discussed is PIWIL1; the disease is infection.