1013
A mixture of the membrane protein KCNJ12 , the soluble TEV protease used to cleave the fusion tag , and the membrane protein HVCN1 , which occurred as a contaminant from an earlier analysis on the same LC column .
 membrane, membrane
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 membrane, membrane