Recent detection of estrogen receptor β (ERβ) during development of the cerebellum [7], and its abundant expression in medulloblastoma clinical samples and in medulloblastoma cell lines [8], [9] implicates this nuclear receptor in normal development, however it also suggests its role in malignant transformation and possibly tumor progression [10], [11], [12], [13], [14]. The gene discussed is ESR2; the disease is neoplasm.