IFNA1 and acquired polycythemia vera: Because type I interferons (IFN) target JAK2 V617F+ progenitors in PV through activation of MAPK and STAT1, thereby increasing TP53 transcription, the combination of IFN with MDM2 inhibitors, which prevent the degradation of TP53, provides an opportunity to induce TP53-dependent apoptosis [170].