Antigen binding proteins that interact with Proprotein Convertase Subtilisin Kexin Type 9 (PCSK9) are described. Methods of treating hypercholesterolemia and other disorders by administering a pharmaceutically effective amount of an antigen binding protein to PCSK9 are described. Methods of detecting the amount of PCSK9 in a sample using an antigen binding protein to PCSK9 are described.本發明描述與前蛋白轉化酶枯草桿菌蛋白酶加工酶9型(PCSK9)相互作用之抗原結合蛋白。本發明描述藉由投與醫藥學上有效量的針對PCSK9之抗原結合蛋白以治療高膽固醇血症及其他病症的方法。本發明描述使用針對PCSK9之抗原結合蛋白偵測樣品中之PCSK9之量的方法。