Strategies for tumor immune escape

The interactions between the immune system and malignant cells play an important role in tumorigenesis. Evidence that tumors are immunogenic continues to accumulate. Although they frequently express antigens in a form recognizable by the host immune system, tumors commonly "escape" the immune response. Tumors may therefore progress by evolving variants that can evade immune responses or by developing other strategies to avoid immune control. The purpose of this review is to evaluate the current status of knowledge concerning these different tumor-escape strategies.