UGT1A1 and breast disorder: Interestingly, UGT1A1 mRNA levels were slightly higher, but not significantly, in more aggressive and advanced stages of breast disease as compared to early stages of breast disease (Stage I/II: 0.3 ± 0.2; Stage III/IV: 0.5 ± 0.3, p = 0.56) (Figure 2C).