Fig. 7: Schematic representation of the consequences of FANCA loss of function in leukaemic progression of TgSpi1 erythroproliferative syndrome.

WT and Fanca-deficient mice exhibit normal erythropoiesis (top). SPI1 overexpression blocks erythroid differentiation at the CFU-E stage and maintains the proliferation of progenitors, allowing the accumulation of spontaneously arising mutations without leading to growth factor independence (middle). The additional absence of the DDR protein FANCA increases the transcription of genes encoding proteins favouring proliferation pathways, such as MDM4, NOTCH and WNT/β-catenin and favours the expansion of clones harbouring Kit or Nras oncogenic mutations conferring EPO independency. This combination of events underlies a rapid leukaemic progression (bottom).