The present invention relates to immunotherapeutic methods, and molecules and cells for use in immunotherapeutic methods. In particular, the present invention relates to the immunotherapy of cancer. The present invention furthermore relates to tumor-associated T-helper cell peptide epitopes, alone or in combination with other tumor-associated peptides, that serve as active pharmaceutical ingredients of vaccine compositions which stimulate anti-tumor immune responses. In particular, the present invention relates to 49 novel peptide sequences derived from HLA class II molecules of human tumor cell lines which can be used in vaccine compositions for eliciting anti-tumor immune responses.