The requirement of HSP binding to peptides to elicit immunogenicity has been shown previously: for example, HSP 70‐associated peptides derived from cancer tissues elicited tumour‐specific immunity.26, 27 We therefore examined the ability of DnaK to bind to aggregates; Western blot analysis demonstrated that DnaK co‐sediments with scFv aggregates, and was therefore bound to aggregates rather than remaining in solution. The gene discussed is HSP90B2P; the disease is cancer.