GFI1B and hereditary elliptocytosis: Intriguingly, the loss of either GFI1 or GFI1B does not prevent formation of IAHCs or the release of HSCs as does the loss of RUNX1 (Okuda et al., 1996; Saleque et al., 2002; Hock et al., 2004; Zeng et al., 2004; Zhang et al., 2019), but the loss of both GFI1 and GFI1B simultaneously completely abrogates the EHT process and leads to failure to produce any HSCs despite the formation of HE cells and the capacity of these cells to generate hematopoietic cells in vitro (Lancrin et al., 2012; Thambyrajah et al., 2016).