In some patients, neutropenia was observed shortly after the first dose [34,91] or the last dose [241], with some requiring hospitalization and pre-emptive antibiotic treatment [211] to control fever, but they did not need to receive granulocytes, whereas in one study it was reported that people with late-onset neutropenia (LON) improved with recombinant granulocyte colony-stimulating factor (GM-CSF) [42]. Here, CSF2 is linked to neutropenia.