The present invention is based, at least in part, on the discovery of compositions and methods useful in the modulation, e.g., inhibition, of gene expression or protein activity. In particular, the present invention is based on novel RNA interfering agents, e.g., siRNA molecules which target apoptosis-related genes or proinflammatory cytokines, and result in reduction, e.g., prolonged reduction, of apoptosis-related gene expression or proinflammatory cytokine expression in cells. Inhibition of apoptosis-related gene expression or protein activity or proinflammatory cytokine expression or protein activity, e.g., by the siRNAs of the invention, inhibits apoptosis-mediated diseases or disorders and proinflammatory cytokine mediated diseases or disorders, including, for example, transplant rejection, hepatitis, liver injury, sepsis, and cancer.