The ITOC series of conferences is the premier meeting for education, scientific exchange and networking within cancer immunotherapy. The fourth edition (ITOC4) will take place on Prague, Czech Republic, from 20 to 22 March 2017. It aims at providing a forum for all professionals working in immunotherapy to discuss early clinical drug development and address the unique challenges of translational research. The programme will focus on the latest challenges and innovations with a special emphasis on combination therapy, immuno-monitoring and biomarker development.