Loss of PAX2 expression has been implicated in the development of endometrial intraepithelial neoplasia (EIN) (Sanderson et al., 2017) and PAX2 is potentially useful in the diagnostic of difficult EIN cases (e.g. where there is no ‘normal’ tissue available to act as an internal control when assessing nuclear morphology) (Quick et al., 2012). The gene discussed is PAX2; the disease is Endometrial Intraepithelial Neoplasia.