Fig. 6. (A) Absence of inguinal lymph nodes in c^IBN mice. Mice were injected intraperitoneally with 1% Chicago Sky Blue in 1xPBS. Two weeks after injection, the skin in the groin of c^IBN (N) and control mice (wild type) was dissected to visualize the inguinal lymph nodes. (B) Peyer’s patches of c^IBN mice are absent or reduced in size and numbers. (Top) Peyer’s patches (arrowheads); Scale bar, 200µm. (Bottom) Plastic sections of PPs.