Background:SUMOylation, a post-translational modification analogous to ubiquitination, attaches a small, ubiquitin-like modifier (SUMO) to target proteins. SUMOylation plays a central role in the immune system by regulating type I interferon (IFN-I) expression, thereby functioning to constrain the innate immune response (Decque Nat Immunol2016), and limit tumor immune surveillance. The SUMOylation pathway is often overexpressed in multiple myeloma (MM) and is associated with poor outcomes (Driscoll Blood2010).