Immunotherapy has been showing impressive outcomes for some cancer patients. However, due to the heterogeneity of cancers, some malignant cells are able to evade immune elimination, which is known as the tumor-escape mechanisms. To make things more complex, each tumor develops its own way of escape, and thus these mechanisms are highly dependent on the host-tumor interactions. Nowadays, it remains a challenge for clinicians to select patients who are most likely to respond to immunotherapy. Therefore, enhancing the efficacy of immunotherapy is of utmost importance in improving patient selection and developing rational combination therapies for these patients.