In breast cancer, SOX2 overexpression is observed in aggressive tumors and associated with a stem cell like phenotype and SOX2OT plays a key role in regulating SOX2. Expression of both SOX2 and SOX2OT are positively correlated in breast cancer samples, with ER+ tumors showing greater expression of both genes than ER- tumors, suggesting that this lncRNA is sensitive to steroid hormones such as estrogens. This evidence concerns the gene ESR1 and breast cancer.