Approximately 80–100% of all myeloma cells express high levels of CD38 protein on their surface, making it a very good therapeutic target.18 CD38 functions as a receptor involved in the transmission of activation and proliferation signals, as well as an ectoenzyme that has a role in calcium signaling and cell survival.19 CD38 receptor-mediated signaling produces a variety of downstream effects, and has variable signaling impact depending on several factors. This evidence concerns the gene CD38 and plasma cell myeloma.