In our previous study, it was indicated that ghrelin inducessevere polycythemia in the rats living in hypoxia (21).In a complementary study, the relation between ghrelinadministration and erythropoietin production has beenelucidated and we concluded that the polycythemic effectof ghrelin was not through erythropoietin upregulation(22). This evidence concerns the gene EPO and polycythemia.