The purpose of the present invention is to discover a target molecule expressed cancer specifically to provide an anticancer agent with which it is possible to treat cancer by acting specifically on this target molecule and to provide a method for testing for cancer the method including a step for measuring a target molecule in a sample. The present invention provides an anticancer agent that includes as an active ingredient an anti transmembrane protein 180 (TMEM 180) antibody or an antigen binding fragment thereof. The present invention also provides a cancer testing method that includes a step for measuring the TMEM 180 level in a sample collected from a subject.
