1913
A common feature of these diseases is the loss of photoreceptor function , also seen in the retinal degeneration slow ( rds or Prph2 Rd2 / Rd2 ) mouse , which is homozygous for a null mutation in Prph2 .
 Disease: retinal degeneration
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: retinal degeneration 
Answer:
 Disease: retinal degeneration