Olivia Thomas, PhD, Karolinska Institute, Solna, Sweden, talks on the importance of characterizing autoreactive T-cell responses in patients with multiple sclerosis (MS). Dr Thomas emphasizes the heterogeneous nature of MS, with patients showing substantial variability in disease course, treatment responses, and clinical symptoms. It is therefore important that MS therapy becomes more tailored to each individual patient. Dr Thomas notes how characterization of individual autoreactive T-cell responses may help achieve this. This interview took place at the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) congress 2021.