While detection of endogenously expressed pS294 and pS118 are readily seen by first immunoprecipitating total ERα and then probing the immunoprecipitate for phosphorylated forms of ERα, we have also shown that our rabbit monoclonal can be used to first immunoprecipitate pS294 from cell or tumor lysates (as shown in Figure 1C, inset). The gene discussed is ESR1; the disease is neoplasm.