| We now use cells lacking expression of TRAF 2 , TRAF 5 , TRAF 6 , IKKalpha , IKKbeta , IKKgamma , TAB 2 , IL 1 receptor associated kinase ( IRAK ) 1 , or IRAK 4 to assess their roles in LMP 1 mediated NF kappaB activation . ^^^ More surprisingly , NF kappaB responses were near normal in TRAF 2 and TRAF 5 double KO MEFs , IKKgamma KO MEFs , TAB 2 KO MEFs , and IRAK 4 KO MEFs but were highly deficient in TRAF 6 KO MEFs and IRAK 1 KO HEK 293 cells . ^^^ |