Genetically modified non-human animals are provided that may be used to model human
hematopoietic cell development, function, or
disease. The genetically modified non-human animals comprise a
nucleic acid encoding human IL-6 operably linked to an IL-6
promoter. In some instances, the genetically modified non-
human animal expressing human IL-6 also expresses at least one of human M-CSF, human IL-3, human GM-CSF, human SIRPa or human TPO. In some instances, the genetically modified non-
human animal is immunodeficient. In some such instances, the genetically modified non-
human animal is engrafted with healthy or diseased human hematopoietic cells. Also provided are methods for using the subject genetically modified non-human animals in modeling human
hematopoietic cell development, function, and / or
disease, as well as reagents and kits thereof that find use in making the subject genetically modified non-human animals and / or practicing the subject methods.