21152
Objective responses have been observed frequently in patients with non - small cell lung cancer ( NSCLC ) harbouring activating EGFR mutations , the most common being deletions in exon 19 and the exon 21 L858R mutation .
 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