FCGRT and plasma cell myeloma: Other factors related to TMDD that might impact the predictions include variations in the expression of the target receptors with disease progression or treatment and the affinity of the drug for the target receptor as well as the affinity for endogenous FcRn and potential competitive binding of M-Protein with FcRn from multiple myeloma patients such as elotuzumab and daratumumab (FDA approved package insert).