Apoptosis in other (A) bat and (B) human cells. Relative fold change of caspase 3/7 activity of bat cells from brain (PaBrT03), fetus (PaFeb5) and lung (PaLuT02), and common human cells from lung (A549), embryonic fibroblasts (HEF) and HeLa cells. All cells were infected with HeV for 24, 48 and 72 hpi at an MOI of 5. Uninfected cells served as the control for each time point. Two sample t-tests were used to compare the relative activity of caspase 3/7 between the control and infected cells at each time point. *P <0.05, **P <0.01.