CD27 and Miyoshi myopathy: To gain further insight into a putative association between clonal T cell expansions in the TME (i.e., high CD27−:CD27+ ratio) and their re-activation upon exposure to lenalidomide, we cultured whole-BM aspirates from MM patients (n = 3) in a 3D organoid for 5 days, and treated with 1 μM lenalidomide +/− an anti-HLA antibody to block TCR-MHC interactions.