In this week’s episode, we will review a study that uses a combination of mouse models to identify IL-19 as a potent cytokine capable of promoting expansion and proliferation of neutrophils, examine the effects of targeted therapies on autoimmune cytopenia in patients with chronic lymphocytic leukemia, and learn about the mechanism of excessive complement activation caused by mutations in factor H-related protein 1 in patients with atypical hemolytic uremic syndrome.