What are disclosed are a method for providing a medicament for treating a malignancy and also cell membranes provided thereby and the use thereof, in which method there is ascertainment of the individual communication structure between the malignancy and the immune system on the basis of a tissue sample containing cells of the malignancy via determination of a malignancy-specific expression pattern of histocompatibility antigens (human leukocyte antigen, HLA) at said tissue sample, there is masking or removal of at least such a portion of the expression pattern which is present at the cells of the tissue sample and which is capable of exerting an inhibitory effect on immunocompetent cells, and there is provision of an individual vaccine for inducing a specific immune response by lysis of those cells at which a portion of the expression pattern was masked or removed.
