Targeted RNA interference against dengue virus infection. Self-complementary RNA with sequences from dengue virus is expressed from a promoter that expresses in the gut of the mosquito soon after a blood meal . This RNA folds into a hairpin conformation with an extended double-stranded region. This double-stranded RNA is cut into 20–25 bp fragments by Dicer. These fragments are bound by the RISC complex of proteins and one strand is removed. The RISC complex is now primed to bind and cleave target sequences from an infecting dengue virus, preventing translation from the RNA and replication of the virus.