Negatively regulated by ERβ1; overexpressed in aromatase inhibitor resistant estrogen receptor-positive (ER+) breast cancer; upregulated after genistein treatment; associated with cycling hypoxia; inversely correlated to metastasis in lung adenocarcinoma; upregulated in head and neck cancer cell lines; downregulated in chronic myelogenous leukemia stem cells; upregulated in T-cell prolymphocytic leukemia. This evidence concerns the gene CYP19A1 and T-cell prolymphocytic leukemia.