title: Quality control of oestrogen receptor assays using frozen breast tumours.
mesh_terms: D001943:Breast Neoplasms / Q000032:analysis*; D005260:Female; D005615:Freezing; D006801:Humans; D011786:Quality Control; D011960:Receptors, Estrogen / Q000032:analysis*
chemical_list: D011960:Receptors, Estrogen