A significant decrease in the risk of grade III/IV neutropenia was seen in patients receiving G-CSF prophylaxis (RR 0.46, 95% CI: 0.28–0.77, I2: 72%, Figure 4A), although the prediction interval still contained the null effect 95% CI 0.09–2.39. This evidence concerns the gene CSF3 and Decreased total neutrophil count.