Imatinib: the narrow line between immune tolerance and activation.

Despite the rapid success of imatinib as a targeted cancer therapy, there seems to be some controversy about its influence on immune function. Research relating to the immunological effects of imatinib has aimed to gain insight into this paradoxical picture, whereby imatinib appears to be on the edge between immune tolerance and immune defence. In addition to the flexibility of several immune effectors, subtle but important experimental variations might explain the seemingly conflicting data, pointing to the possible use of imatinib to modulate immune responses against tumours. The clinical use of imatinib, and its putative immunomodulatory properties, represent challenging issues still to be resolved.