ABCG2 was previously found up-regulated in different types of cancer [22,48,49], while the analysis of freely available TCGA data support our qPCR and IHC analysis and show that ABCG2 mRNA levels are lower (z score median −2.5) in endometrioid EC versus control tissue and correlate with significantly longer overall survival of patients (TCGA cohort of 1227 patients with endometrioid EC at The cBioPortal for Cancer Genomics; www.cbioportal.org, accessed on 16 October 2020). The gene discussed is ABCG2; the disease is cancer.