Mice were injected with TMPRSS6 siRNA (which has been shown to cause sustained knockdown of murine Tmprss629) or NTC siRNA every 3 weeks for a total of 3 injections starting 1 week after tamoxifen induction of the mutant Jak2-V617F (Figure 6A), at which time mice with PV had a MPN phenotype (supplemental Figure 7). The gene discussed is TMPRSS6; the disease is acquired polycythemia vera.