To gain insight into the potential involvement of active PHB, MEKK1 and/or NIK in the Ras/Raf and IKKα/β/IκB/NF-kB signaling, lung cancer cells were transfected with pBio-PHB or pD-PHB to generate biotin-labeled or plasma membrane-bound active PHB, respectively, and then co-immunoprecipitated with anti-IKKα/β or anti-PHB antibodies (Figure 3C and 3D). Here, RAF1 is linked to lung carcinoma.