Immune checkpoint inhibition has rapidly changed the treatment paradigm of several cancer types, including non-small cell lung cancer (NSCLC), melanoma, urothelial cancer and renal cell carcinoma (RCC). Lots of research is currently focused on the search for biomarkers that can predict whether a patients will respond to immunotherapy or not. During his lecture at BMUC 2018, Dr. Mark Kockx, pathologist and founder of HistoGeneX shared his views on this matter.