SOX2 and neoplasm: We compared the expression of NOTCH-1 and its downstream targets (AKT, c-MYC, OCT3/4, SOX2, NANOG) together with the cell cycle regulatory protein p21 and the proliferative marker Ki-67 in paired biopsies from the original tumor at the moment of the diagnosis (2019) with the more recent one (2023) after mCHT in first-line followed by MTD chemotherapy in second-line.