 This protein only binds long dsRNAs, but the mechanism producing this length specificity is unknown.This RNA-binding protein then facilitates the transfer of cleaved siRNAs to the RISC complex.In "C. elegans" this initiation response is amplified through the synthesis of a population of 'secondary' siRNAs during which the dicer-produced initiating or 'primary' siRNAs are used as templates.