The use of genes for performance enhancement: doping or therapy? R.S. Oliveira, T.F. Collares, K.R. Smith, T.V. Collares and F.K. Seixas. Braz J Med Biol Res 2011; 44: 1194-1201.

Figure 1. Targeted tissues and organs for gene doping. Main aims of gene doping to enhance sports performance: improvement of pain tolerance (endorphin/enkephalin genes), muscle quality and vascularization (VEGF gene and myostatin antagonists) and erythrocyte number (EPO gene). With more genomic understanding, other organs will be targeted in the future, such as heart and kidneys, to increase cardiac output and EPO production, respectively. VEGF = vascular epithelial growth factor; EPO = erythropoietin.