| Characterization of Pellino 2 , a substrate of IRAK 1 and IRAK 4 . ^^^ In an attempt to discover novel signal transducers in TIR signaling , we identified human Pellino 2 as an interaction partner of IRAK 4 . ^^^ Pellino 2 interacts with kinase active as well as kinase inactive IRAK 1 and IRAK 4 . ^^^ Furthermore , Pellino 2 is one of the first substrates identified for IRAK 1 and IRAK 4 . ^^^ |