**4. Pilot clinical data supporting HBO role in HSC transplantation**

To date, two pilot clinical trials exploring HBO in UCB transplantation as well as autologous hematopoietic cell transplantation (HCT) have been completed. In both studies HBO was given in standard fashion at least 6 hours prior to HSCP infusion on day 0 of their transplant (**Figure 5**). The first aim of these studies is to examine the safety and tolerability of HBO in the setting of HCT. In addition, these studies explored the impact of HBO on blood count recovery as well as EPO levels posttransplant. Details of HBO therapy and the results of these studies are being summarized in the next three paragraphs.