UGT1A1 and neutropenia: These findings are similar to those reported by Iwasa et al. who detected a 46% rate of grade ≥ 3 neutropenia in a population of East-Asian patients with homozygous genotypes (or heterozygous UGT1A1*28 and *6 haplotypes) who received a reduced starting dose of irinotecan equal to 150 mg/m2 [20].