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Each receptor must therefore engage a unique subset of the available signaling elements - - at least partly through the selection of proteins with src - homology 2 domains ( SH2 proteins ) .
 GENE: src - homology 2 domains; GENE: SH2 proteins
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: src - homology 2 domains; GENE: SH2 proteins