IKZF1 and plasma cell myeloma: Degradation of IKZF1 and IKZF3 causes the downregulation of interferon regulatory factor 4 and cMYC, which play a role in proliferation and survival of myeloma cells.25, 26, 27 On the contrary, the immunological activity of lenalidomide comprises co‐stimulation of T cells,28, 29 enhancement of the type 1 T helper–mediated immune response,9, 30, 31 enhancement of natural killer (NK) and NK T cells,10, 32, 33, 34, 35 and inhibition of regulatory T cells.36