Cathepsin B is reported to be predominantly located in placental and decidual macrophages, which may be important in mediating villous angiogenesis and decidual apoptosis, and cathepsin L is found to be expressed in invasive cytotrophoblasts(1).Both cysteine proteases are determined to have critical roles during normal placentation and in the etiology of preeclampsia(1). This evidence concerns the gene CTSB and preeclampsia.