Through a small-scale screening with FDA-approved compounds, we found that lovastatin, a small natural chemical (MW 404 Da), increases the expression of miR-33b and down-regulates c-Myc expression and function in medulloblastoma cells with an endogenous miR-33b gene; lovastatin treatment also attenuates the growth of tumours orthotopically xenografted with these cells. This evidence concerns the gene MYC and neoplasm.