RIGI and sarcoma: RIG-I has been estimated to be expressed at ~1000 copies per cell at the upper end of expression (in innate immune cells such as macrophages32) while circCsnk1g3 and circAnkib1 were expressed in the sarcoma cells at ~2200 and 400 copies per cell, respectively (Supplementary Fig. 3E), which would potentially allow for an approximately equimolar interaction.