Xiao and Hu. (2017) found that the incidence of AMS was lower after five HBO pre-treatments compared to the control group (30% vs. 90%). Liu et al. (2011) found that three HBO pretreatments reduced the levels of interleukin 6 (IL-6) and MMP-9 in mice with AMS, but the difference was not significant. The gene discussed is MMP9; the disease is ablepharon macrostomia syndrome.