1572
RESULTS: Both the epithelium and subepithelium of the tarsal and bulbar conjunctiva of patients with VKC , but not those of four nonatopic control subjects , showed intense positive staining for estrogen and progesterone receptors .
 protein: progesterone receptors
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 protein: progesterone receptors