4054
The goals of these experiments were to determine whether lactational anestrus would be prolonged by a 48 - h fast at days 13 and 14 postpartum ( pp ) and , if so , to determine whether this effect could be reversed by treatment with the Ob protein leptin .
 GENE: Ob protein; GENE: leptin
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: Ob protein; GENE: leptin