MCL1 and plasma cell myeloma: Resistance to ABT‐199 occurs very quickly resulting in rapid disease relapse.41, 42 Overexpression of Mcl‐1 has been observed in various cancers including MM and plays a major role in myeloma cell survival and resistance to chemotherapy.43, 44 Due to these limitations, there has been great interest in combining ABT‐199 with other agents to augment ABT‐199's activity in patients without a t(11;14) translocation, and to prevent drug resistance to ABT‐199.