In the subsequent 4 cycles of ddP ± trastuzumab treatment which was adjusted according to the protocol, 20/40 (50%) patients, 26/40 (65%) patients, 38/40 (95%) patients and 40/40 (100%) patients received 3 mg PEG-G-CSF administration respectively, no patients reported grade3/4 neutropenia (Table 4). The gene discussed is CSF3; the disease is neutropenia.