ASXL1 and acquired polycythemia vera: When it comes to the analysis of ASXL1 solely, we detected variants of this gene in 3% of pts who did not progress to post-PV-MF and in 23% who had, which it is in good agreement with results of Guo et al. (4 vs 26%) who demonstrated that PV patients with coexisting mutations of ASXL1 had a poor MFFS (Guo et al. 2019).