Johannes Huppa, PhD, Medical University of Vienna, Vienna, Austria, explains how a better understanding of T-cells can improve the sensitivity and affinity of CAR T-cell therapy. Dr Huppa believes that in order to achieve these, we have most likely to shift away from current formats of CARs and move towards the T-cell receptor. This interview took place at the 2nd European CAR T-Cell Meeting in Sitges, Spain.