Strikingly, simvastatin treatment administered after the onset of obesity (Figure 1a) led to invasive cancerous lesions with an incidence of 45%, a phenotype only achieved in this mouse model when both copies of Pten are lost in the prostate epithelium [10, 13] (Figure 1c, 1d). This evidence concerns the gene PTEN and obesity due to melanocortin 4 receptor deficiency.