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.