GADD45B and plasma cell myeloma: 6, 7 The latter protein interacts with the JNK activating kinase MKK7 inhibiting its catalytic activity.8, 9 Previous results from GADD45β knock-out mice revealed that targeting this protein has no effect on overall health, pointing to a redundant role on normal cell and, at the same time, a potential feasible target on cancerous cells.10 Tornatore et al.5 probed GADD45β expression in various cancers and found it to be highly elevated in several tumours, and especially in multiple myeloma (MM) samples.