PGR and neoplasm: AP-2α isoform: AP-2α/β protein expression was studied in 266 ER negative patients and showed no significant association with tumour size, lymph node stage, histological grade, prognosis (NPI), development of metastasis, vascular invasion, tumour type, menopausal status, PgR, HER3, E-cadherin, EGFR, CK14, p53 or Bcl2 (data not shown).