Since RMST physiological and functional roles involve its ability to interact with SOX2 transcription factor [23] and an inverse regulation of RMST in comparison to SOX2 levels in human and mice TC samples was observed, we investigated the levels of SOX2 in cells with or without enforced expression of RMST, together with the expression of several other stemness markers (NANOG, OCT4, ABCG2, ALDH, CD38, CD133) since SOX2 in TC is a master regulator of cancer stem cells [25, 26]. The gene discussed is ABCG2; the disease is cancer.