CASP3 and cancer: Because classical apoptosis and necroptosis have been implicated in vaccinia virus infection to varying degrees,24 depending on the strain of the virus and molecular mechanisms that may differ in various cells,25 we next analyzed expression of cleaved caspase-3 as well as phosphorylated receptor-interacting protein kinase (RIP1) in cell lysates prepared from the OVV- and/or DOX-treated cancer cells, which would help to differentiate between the induction of apoptosis and necroptosis, respectively.26