6173
Neither RD19 nor RD21 mRNA synthesis was responsive to cold or to heat stress .
 GENE: RD19; GENE: RD21 mRNA
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: RD19, RD21 mRNA 
Answer:
 GENE: RD19; GENE: RD21 mRNA