First, you would need to know the sequence for erythropoietin. Then you would have to find the mRNA for the protein by using degenerate probes. Once you have isolated the mRNA, you can make cDNA with reverse transcriptase. This DNA can then be cloned into appropriate restriction sites and expressed in bacteria. This compound is used to stimulate red blood cell production in kidney patients, who become anemic, and professional athletes who want to feel like they trained at altitude without actually having to live at altitude. The latter practice is illegal in all sports.