AMPH and breast cancer: Amphiphysin is involved in synaptic vesicle endocytosis by promoting the division of lattice-protein encapsulated vesicles, which leads to partial failure of message transmission when it is attacked by antibodies.[3,4] They are a relatively uncommon autoantibody in patients with SCLC, regardless of the combination of PNS.[5–7]In 1993, De Camilli[8] first reported 3 cases of female breast cancer patients with stiff-person syndrome.