CD22 and acute lymphoblastic leukemia: Inotuzumab Ozogamicin (InO), a monoclonal IgG antibody that targets CD22 on malignant B cells inducing double‐strand DNA breaks [9], was approved by the European Medicine Agency (EMA) for use in adult patients with relapsed/refractory ALL in June 2017 [10], incorporated into the National Institute for Health and Care Excellence (NICE) guidelines in the UK in 2019 [11], and approved by the Chilean Public Health Institute in July 2019 [12].