Expression levels of membrane complement regulatory proteins (mCRPs) CD46, CD55, and CD59 were examined in primary uterine serous carcinoma (USC), and the ability of small interfering RNA (siRNA) targeting these mCRPs to enhance USC sensitivity to complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) induced by trastuzumab was evaluated in vitro. Here, CD46 is linked to endometrial serous adenocarcinoma.