Evidence-based guidelines recommend that G-CSFs are used as prophylaxis for FN in patients with cancer receiving a high-risk (≥20%) chemotherapy regimen, or an intermediate-risk (10%-20%) regimen if ≥1 risk factor is present.1,8,16 In response to the COVID-19 pandemic, ASCO, ESMO, and NCCN released guidance on G-CSF administration to reduce the infection risk in patients with cancer at risk of FN. Here, CSF3 is linked to infection.