CYP19A1 and ovarian hyperstimulation syndrome: Although Hu‐17 at various concentrations (0.034, 0.1028, 0.3086, 0.925, 2.77, 8.33, 25, and 75 μmol/L) had no detectable effect on aromatase activity when measured in vitro using a recombinant aromatase activity assay (Figure 3C), it decreased aromatase expression in both ovarian granulosa cells from OHSS patients (Figure 3D) and KGN cells (Figure 3E,F).