A more recent, similarly retrospective report looked into risk factors for adverse outcome in 80 patients with MPN-SVT (mostly PV) [154]; at a median follow-up of 11 years, 13% of the patients experienced an adverse outcome and were enriched for cases with ≥50% JAK2V617F allele burden, and additional mutations (spliceosome or TP53); MPN-SVT patients with at least one of the latter two risk factors displayed inferior event-free (81% vs 100%) and overall (89% vs 100%) survival at 10 years. The gene discussed is TP53; the disease is acquired polycythemia vera.