Specifically, SNPs in the PFKFB3 gene encoding 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3, a critical regulator of glucose metabolism, have been found to impair macrophage effector functions and predispose transplant recipients to IPA (100). This evidence concerns the gene PFKFB3 and Ito hypomelanosis.