IL2 and plasma cell myeloma: Based on the evidence above that IL-2 production is enhanced but quickly consumed in elotuzumab or elotuzumab plus lenalidomide-treated co-cultures as compared with lenalidomide alone, we hypothesized that IL-2 produced by CD3+/CD56+ cells contributed to the elotuzumab or elotuzumab plus lenalidomide-mediated NK-dependent myeloma cell killing.