Moreover, little is known about the COVID-19 complications that may be triggered by the use of granulocyte colony-stimulating factors (G-CSF) in a SARS-CoV-2-infected donor, which is consistent with the need of a negative SARS-CoV-2 PCR screening test for the donor before starting hematopoietic stem cell (HSC) mobilization, as required by some, but not all, donor registries and as recommended by EBMT guidelines. Here, CSF3 is linked to COVID-19.