55904
According to this research , genetic markers commonly found in modern humans worldwide suggest that today many people carry a gene that evolved as protection against the brain diseases that can be spread by consuming human brain tissue .
 brain diseases
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 brain diseases