However, no significant changes were observed in the levels of caspase-3 in MSC/NDV in comparison with control groups (PBS and MSC) that may be due to the occurrence of non-apoptotic pathway rather than apoptosis one, since sometimes viral infection leads to activation of other programmed cell death such as necroptosis in a caspase-8-dependent pathway. Here, CASP3 is linked to viral infectious disease.