We describe (1) a method of enhancing antigen presentation, comprising the step of supplying to an antigen presenting cell such as a dendritic cell, or precursor cell, an inhibitor of Toll-related receptor (TRR) signalling and (2) a method of inhibiting antigen presentation, comprising the step of supplying to an antigen presenting cell such as a dendritic cell, or precursor cell, an enhancer of Toll-related receptor (TRR) signalling. The inhibitor of TRR signalling may be a dominant negative mutant of MyD88, for example MyD881pr.