This showed that C4 genes, which are down-regulated in the corpus mucosa of atrophy subjects, are indeed strongly associated with expression in healthy corpus mucosa (p = 7.4 × 10-6; Table 3), while A1 genes, which are up-regulated in the antrum tissue of atrophy subjects, are not significantly associated with expression in normal corpus mucosa (p =1; Table 3). This evidence concerns the gene C4A and Atrophy.