We first investigated the expression of PD-L1 on tumor cells in bone marrow (BM) samples from a large number of patients with newly diagnosed (ND) MM (n = 37), daratumumab-naïve relapsed/refractory (RR) MM (n = 43; median of 3 prior lines of therapy), and daratumumab-refractory MM (n = 41; median of 6 prior lines of therapy). The gene discussed is CD274; the disease is neoplasm.