Statistical analysis showed that UGT1A1*6 G/A + A/A patients had a higher risk of grade 3~4 diarrhea as compared to G/G patients, with statistically significant difference (χ2 = 11.364, p = 0.001), and also a higher risk of grade 3~4 neutropenia as compared to G/G patients (χ2 = 5.727, p = 0.017). Here, UGT1A1 is linked to Decreased total neutrophil count.