159
Here , we present evidence for a model in which mRNA sequences up to around 100 nucleotides downstream from the start codon of 21K fold back and base - pair to the 21K translation initiation region , thereby decreasing the translation initiation frequency .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities:  
Answer:
 None