Preclinical models of multiple myeloma: a critical appraisal.

Introduction: Preclinical models, by definition, are an approximation of reality, and their use in developing anticancer drugs is eagerly explored. Positive clinical correlations have been identified with different test systems, in addition to limitations and a need to improve preclinical model systems. Predicting whether a potential new anticancer agent will have a positive therapeutic index in patients remains a challenge.