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Inactivation of both alleles of the RB1 gene during normal retinal development initiates the formation of a retinoblastoma ( RB ) tumor .
 Disease: retinoblastoma ( RB ) tumor
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Disease 
Text: {0} 
 Entities: retinoblastoma ( RB ) tumor 
Answer:
 Disease: retinoblastoma ( RB ) tumor