FOLFOXIRI + anti-EGFR antibody arm seemingly showed a higher risk of diarrhea (RR 1.82, 95% CI 0.78–4.24, I2 = 0%) and a lower risk of neutropenia (RR 0.76, 95% CI 0.48–1.2, I2 = 0%), but no significant difference between two arms (P > 0.05) (Fig. 5). This evidence concerns the gene EGFR and Decreased total neutrophil count.