- Ectopic expression of the murine chemokines CCL21a and CCL21b induces the formation of lymph node-like structures in pancreas, but not skin, of transgenic mice. Chen, S.C., Vassileva, G., Kinsley, D., Holzmann, S., Manfra, D., Wiekowski, M.T., Romani, N., Lira, S.A. J. Immunol. (2002)