Iron toxicity and hematopoietic cell transplantation: do we understand why iron affects transplant outcome?

In the last decades, we have witnessed huge progress in the understanding of iron metabolism and the consequences of its dysregulation in case of overload, and we have understood how, in the case of hematopoietic transplantation, the toxicity of iron and the related damage acquired over the years is important in addition to the overload itself. This article summarizes and discusses, in real-world practical examples, what knowledge has been acquired, how much can be translated into clinical practice today, and how much is best explored only in a well-defined and controlled experimental environment.