Brain Transcriptome Database (BrainTx)http://rdf.ncbi.nlm.nih.gov/pubmed/

M A. Wurbel, et.al., Mice lacking the CCR9 CC-chemokine receptor show a mild impairment of early T- and B-cell development and a reduction in T-cell receptor gammadelta(+) gut intraepithelial lymphocytes., Blood, 2001, 98
http://rdf.ncbi.nlm.nih.gov/pubmed/11675330