There is little information about the capacity of C6 glioma cells to growth in the presence of aromatase inhibitors; however, by analogy to the implications of aromatase in other forms of oestrogen-sensitive tumours, such as breast tumours, it is conceivable that the modulation of the activity and expression of aromatase by pharmacological concentrations of melatonin may play a role in the growth of glioblastomas. The gene discussed is CYP19A1; the disease is glioma.