Ever since the IMF launched the Black Swan Research Initiative (BSRI) in 2012 to find the pathway to a cure for multiple myeloma, the project has focused on achieving and documenting minimal residual disease (MRD), the lowest level of disease possible with currently available therapies. However, with both early disease (monoclonal gammopathy of undetermined significance, MGUS, and smoldering multiple myeloma, SMM) and after therapy, many patients can do well even with obvious residual disease. As the BSRI team is learning, MRD assessment is but one step to understanding how myeloma progresses. We can gain even further insight by examining the role of immune cells, the key factor in controlling residual disease.