IL2 and plasma cell myeloma: The mechanism of action is thought to include co-stimulation of T-cells via the B7-CD28 pathway leading to increased production of interleukin 2 (IL2) and interferon gamma (IFNy), which ultimately results in downstream natural killer (NK)-cell mediated antibody-dependent cellular cytotoxicity (ADCC) towards myeloma cells [22, 23].