Dendritic cells are highly specialised antigen-presenting cells, which can be used for immunotherapy trials. Functionally normal DCs play a critical role in the activation and potentiation of tumour antigen-specific responses, but in some cases they can be defective. The aim of study were analysis of phenotype, finding of differences and/or functional defects in DCs generated from multiple myeloma and monoclonal gammopathy of unknown significance subjects when compared with healthy volunteers under serum-free and/or autologous conditions.