In humans, a phase 1 study conducted in children with relapsed/refractory solid and central nervous system tumors reported that plasma interleukin 6 (IL-6) concentrations consistently decreased over time, returning to normal values in all patients after three weeks of simvastatin, in association with topotecan and cyclophosphamide on days 1–5 [78]. This evidence concerns the gene IL6 and central nervous system cancer.