Hematopoietic stem cells (HSCs) are one of the most widely utilized stem cell populations in the clinic today. Defects in HSC result in numerous hematologic diseases such as myelodysplastic syndromes (MDS). Our research focuses on uncovering the molecular mechanisms underlying how HSCs form, how they respond to injuries, and what goes awry in HSC diseases. Our studies combine the advantages of zebrafish and human cells to explore the development and genetic regulation of HSC biology. Zebrafish offer powerful genetic pliability, easily accessible in vivo imaging, numerous transplantation assays, and screening capabilities. Human cells allow us to decipher the conservation of our novel zebrafish findings to relevant human diseases and treatments. Through these studies, we anticipate identifying factors that are critical in the HSC formation and function, which can be used to inform therapeutic strategies to improve HSC function as well as HSC derivation from pluripotent stem cells.