This animation goes along with a video of a postdoc describing her research in RNA interference. She starts by explaining that a short stretch of double-stranded RNA is complementary to a stretch of DNA in the genome. When the interfering RNA enters the cell, it binds to and is separated into single strands by a multi-protein complex called RISC. RISC tosses one strand out and then uses the remaining one to guide it to mRNA that bears complementarity to the short interfering RNA strand. Once that mRNA is found, a protease within the complex destroys it so that it can no longer be translated into protein. The hope is that this could be used to combat diseases that are manifested by overexpression of certain proteins.