In their sociological study, Martin S. Weinberg and Colin J. Williams interviewed 26 "men sexually interested in transwomen" (MSTW). Thirteen identified themselves as heterosexual, and 13 as "bisexual or probably bisexual." The authors opined "These labels only superficially describe their sexual interest," and noted that the expressed interest in trans women was sometimes used as a basis for denying a more stigmatized self-identity. As an example, they described a case who "said that he was 'bisexual' rather than 'gay' because he was able to think of the transwomen as women".