HEY1 and systemic lupus erythematosus: M2b macrophages also express high levels of NOTCH1IC as well as elevated Hes1 and Hey1. Furthermore, GSI treatment in a mouse model of SLE impaired macrophage differentiation into the M2b phenotype and ameliorated lupus-associated symptoms, which included reduced anti-dsDNA titers, decreased kidney scores, and attenuated IgG deposition (19).