We next examined the distribution of CVA19 in the small intestine, and found that CVA19 viral RNA and cleaved-Caspase 3 co-localized in small intestinal villi cells (as indicated by the white arrows), and the expression level of cleaved-Caspase 3 was higher in the infected mice, indicating that viral infection led to apoptosis in small intestine (Figure 6(E)). The gene discussed is CASP3; the disease is viral infectious disease.