A Comment article suggest that based on these results, and the fact that the population of patients included in the trial was particularly refractory to other treatments, such as anti-TNFα and immunosuppressants, “etrolizumab has great potential to become a new therapeutic option for patients with ulcerative colitis.” These data support the case for further studies to validate clinical efficacy and long-term safety of etrolizumab in this group of patients with difficult-to-treat disease.