For the CUP and EAP studies, the protocols stated that primary prophylaxis with G-CSF (defined as use during Cycle 1; secondary prophylaxis defined as use in any subsequent cycle) should be considered in patients with high-risk clinical features that may predispose them to increased complications from prolonged neutropenia (≥65 years of age, poor performance status, previous episodes of febrile neutropenia, extensive prior radiation ports, poor nutritional status, or other serious comorbidities). Here, CSF3 is linked to Decreased total neutrophil count.