HPSE2 and hemophilia: The fact that transduced livers expressed HPSE2 transcripts, and the observation that heparanse-2 is a secreted protein (Levy-Adam et al., 2010; Beaman et al., 2022), raises the possibility that the livers of treated mice may act as a factory to produce heparanase-2 that then circulated and had beneficial effects on the LUT, akin to gene therapy to replace coagulation factors missing in haemophilia (Chowdary et al., 2022).