CYP19A1 and cancer: According to them, 6,8-diprenylorobol showed potent cytotoxic effects toward HL-60 human leukemia cells with an IC50 value of about 10 μM. Although it was not a direct study to show the anticancer activity of 6,8-diprenylorobol, Sun et al. reported that 6,8-diprenylorobol inhibited aromatase, one of the targetable enzymes for cancer therapy, with a Ki value of 1.42 μM [43].