EPO and leukemia: Recently, EPO has also been suggested to act on hematopoietic stem and progenitor cells (HSPCs) (Cheshier et al., 2007; Shiozawa et al., 2010; Grover et al., 2014; Giladi et al., 2018; Yang et al., 2017; Tusi et al., 2018; Singh et al., 2018; Dubart et al., 1994), but the nature of EPO’s effect on HSPC fate remains unresolved despite potential adverse side effects during long-term EPO usage in the clinics and associations of high EPO levels with leukemias (Ma et al., 2010; Weinreb et al., 2020; Li et al., 2015).