“…CD47 acts, presumably, as a signal to monocyte‐macrophages to not phagocytose the cells, and anti‐CD47 can block the “don't eat me” signal and allow cells to be phagocytosed. When anti‐CD47 is administered to certain cancer patients, it is given at very high dosage, which creates huge problems for transfusion services during their serologic evaluations related to type and screen and provision of compatible blood . In the paper by Reyland et al, in this issue of Transfusion Medicine , the authors present two case studies of patients who are receiving anti‐CD47.…”