| By using co immunoprecipitation techniques and in vitro kinase assays , the uPAR associated proteins were identified as Janus ( Jak ) and Src non receptor protein tyrosine kinases ( PTK ) Jak 1 , Tyk 2 , and p 59 ( fyn ) , p53 / 56 ( lyn ) , p53 / 59 ( hck ) , and p 55 ( fgr ) . ^^^ |