Abs that recognize such glycosphingolipids (GSLs) as GD2, GM2 and LewisY (LeY) mediate complement-dependent cytotoxicity and have been suggested to be more cytotoxic to tumor cells than Abs that recognize proteins Ag or TACAs (84), which kill tumor cells by Ab-dependent cellular cytotoxicity. This evidence concerns the gene DDX41 and neoplasm.