SOX2 and breast cancer: Fourth, immunohistochemical analysis of breast cancer patient tissue samples revealed higher expression of CSC-related stemness genes (OCT4, SOX2, and NANOG) along with Treg marker FOXP3, in chemotherapy-treated cohort (n = 5), as compared to non-chemotherapy treated group (n = 5) (Online Resource 4, Supplementary Fig. 2D).