Gastric mucosa of different degrees of chronic inflammation and association of HEV-like vessels with progression of inflammation. (A) (Upper) Gastric mucosa at a mild stage barely expresses HEV-like vessels with minimum recruitment of lymphocytes. (Lower) Gastric mucosa at a marked stage expresses a significant number of recruited lymphocytes (arrowheads) around HEV-like vessels. (B) The number of MECA-79+ or HECA-452+ vessels is positively correlated with the progression of chronic inflammation. Each group consists of 11 (normal), 42 (mild), 67 (moderate), and 23 (marked) patients. (C) The number of patients exhibiting greater than 1% MECA-79+ or HECA-452+ vessels is highly correlated with progression of chronic inflammation. *, P<0.05; **, P<0.01;, P<0.001; NS, not significant. Bar = 50 μm. Adapted with permission from Kobayashi, M.; Mitoma, J.; Nakamura, N.; Katsuyama, T.; Nakayama, J.; Fukuda, M. Proc. Natl. Acad. Sci. U. S. A., 2004, 101(51), 17807–17812, Copyright 2004 National Academy of Science, USA.