Washington Scientists have identified a hormone that significantly extends the lifespan of mice, a discovery that could mark a crucial step toward developing drugs that boost longevity in people.
Washington scientists have already found the key to extending human life. 
They have found the key to extending the life of Mice not humans. 
( z1 find :ARG0 ( z2 scientist :location ( z3 city :name ( z4 name :op "Washington" ) ) ) :ARG1 ( z5 key :ARG1 ( z6 extend :ARG1 ( z7 live :ARG0 ( z8 human ) ) ) ) :time ( z9 already ) )