In a previous study, the HIF1α polymorphism at +45319C>T (the 1772C>T in our study) and several other loci are associated with idiopathic osteonecrosis of the femoral head (ONFH) in Korean men [22], [30], [31], suggesting that HIF1α variations play a role in the pathogenesis of ONFH. This evidence concerns the gene HIF1A and idiopathic osteonecrosis of the femoral head.