UGT1A4 and neoplasm: However, in pooled tumor HLMs, the metabolic activities of UGT1As and UGT2B7 were significantly decreasing, such as UGT1A (Vmax1: 2.21 ± 0.05 nmol/mg protein/min; Vmax2: 0.04 ±0.33 nmol/mg protein/min), UGT1A1 (63.04 ± 3.60 pmol/mg protein/min), UGT1A4 (226.80 ± 63.37 pmol/mg protein/min), UGT1A9 (524.03 ± 16.62 pmol/mg protein/min) and UGT2B7 (405.48 ± 19.23 pmol/mg protein/min) (Table 2).