CD4 and neoplasm: Idiotypes are the variable regions of the immunoglobulin that binds to the antigen and since they are expressed in a unique pattern on a given malignant B cell, they can serve as a tumor-specific antigen to elicit antitumor CD4 and CD8 T cell responses: the results of different trials using this strategy in immunotherapy has been nicely reviewed by Kwak and colleagues [92].