In this special issue of the Chinese Clinical Oncology focusing on Cancer Immunotherapy. Beyond the "hot" area of immune checkpoint inhibitors and CAR T cell therapy, this issue also explores other emerging concepts of immunotherapy such as combination with radiation therapy, oncolytic viruses, and overcoming the inhibitory tumour microenvironment with indoleamine 2,3-dioxygenase (IDO) inhibitors and other similar microenvironment modulating drugs.
