33740
However , variations of KDEL and KKXX do occur , and other sequences can also give rise to endoplasmic reticulum retention .
 location: KKXX
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: KKXX 
Answer:
 location: KKXX