The safety and tolerability of hLF 1-11 has to be established first in HSCT recipients who are at risk of developing, but have not yet developed, infectious complications due to invasive fungal disease. These patients are different from healthy volunteers because they have received myeloablative treatment which not only arrests haematopoiesis resulting in neutropenia but also induces mucosal barrier injury both of which predispose to infections which typically occur during the week after transplant. It is therefore essential to know that hLF 1-11 is when given during neutropenia and mucosal barrier injury before infections ensue