16884
Since the TRPV1 - 4 , TRPA1 and TRPM8 channels from this family play a pivotal role in both the detection and possibly modulation of painful stimuli , they are regarded as a very promising target of novel analgesic drugs .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None