Several G-CSF drugs have been marketed to manage neutropenia for subcutaneous administration including filgrastim [3], pegfilgrastim [4], lipegfilgrastim [5], and eflapegrastim [6] with the indication to decrease the incidence of infection, as manifested by febrile neutropenia, in patients with non-myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with a clinically significant incidence of febrile neutropenia. This evidence concerns the gene CSF3 and neutropenia.