Deletion mutants of MEN that disrupt inhibitory functions on p53-mediated transactivation. HeLaS3 cells were transfected with 2 μg of 2x RGC-Luc, 2 μg of CMVp53, and 2 μg of pME18S-MEN(HA), pME18S-MLL/MEN(HA), pME18S-tMLL(HA), or one of the expression vectors of MEN mutants by using a calcium phosphate method and were assayed in the same way as in Fig 1.