2997
Among natural killer ( NK ) cells , highly active NK cells ( CD 16 + CD 57 - ) markedly increased shortly after BMT , and gradually returned to normal .
 Anatomy: natural killer ( NK ) cells; Anatomy: NK cells
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Anatomy 
Text: {0} 
 Entities: natural killer ( NK ) cells, NK cells 
Answer:
 Anatomy: natural killer ( NK ) cells; Anatomy: NK cells