Instruct: Identify the main category of Biorxiv papers based on the titles
Query: Brain endothelial CXCL12 attracts protective Natural Killer cells during ischemic stroke
25
The categories of this paper are: bioengineering
13
The categories of this paper are: animal
12
The categories of this paper are: behavior
31
The categories of this paper are: paleontology
3
The categories of this paper are: evolutionary
19
The categories of this paper are: epidemiology
14
The categories of this paper are: biophysics
32
The categories of this paper are: zoology
7
The categories of this paper are: ecology
8
The categories of this paper are: genomics
27
The categories of this paper are: pathology
9
The categories of this paper are: synthetic
10
The categories of this paper are: and
2
The categories of this paper are: biology
17
The categories of this paper are: molecular
22
The categories of this paper are: physiology