CD38 and plasma cell myeloma: The CD38 antigen is a type II transmembrane glycoprotein with receptor and enzyme functions that is expressed in a number of hematological malignancies, particularly in multiple myeloma (MM).146 In addition, its expression has also been reported in lymphomas such as MCL147 and NK/T-cell lymphoma (NKTCL).148 Daratumumab is a CD38 mAb approved for treating relapsed or refractory and untreated MM.