Organized by Assist. Professor Werner Haselmayr and Medina Hamidović, MSc (Institute of Communications Engineering and RF Systems), the fourth annual International Workshop on Molecular Communications took place at the JKU this year. Scientists from eight countries and various disciplines attended the workshop. Molecular Communications is a relatively new field of research, laying the foundation for many future applications in health and the environment, such as "Smart Infrastructure Monitoring", "Smart Drug Delivery", or "Internet of Bio-NanoThings".