5′-triphosphate-siRNA: turning gene silencing and Rig-I activation against melanoma

siRNA is used to silence expression of a specific gene and, if modified by a triphosphate at the 5′ end, will also activate the helicase Rig-I, leading to interferon production. Poeck et al. now combine both of these activities in a single siRNA to kill melanoma cells by crippling a crucial tumor cell survival pathway and triggering an interferon-dependent antitumor immune response (pages 1152–1153).