Crispr-Cas9 system discovered in bacteria Tells us how smart they really are They fight the phages, their dire foes Cutting them up like weeding hoes Scientists found this so incredulous Thought they could use it to fight diseases Find the Crisprs in human genes Edit them and quell sickness scenes Locate the genes in DNA, Design the guide RNA Send it into the cell, To ring the bell Cas9 executes the cut, Cell machinery prepares to shut Add, insert or delete, the work done is neat New protein from edited gene Makes disease a past scene Renewed health and humanity Crispr-Cas9 is extraordinary