2320
The continuing development of ligands that function as selective estrogens or antiestrogens for ERalpha or ERbeta should allow optimized tissue selectivity of these agents for menopausal hormone replacement therapy and the treatment and prevention of breast cancer .
 GENE: ERalpha; GENE: ERbeta
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities: ERalpha, ERbeta 
Answer:
 GENE: ERalpha; GENE: ERbeta