IL6 and gastric carcinoma: In AGS human gastric carcinoma cells, H. pylori infection promotes the secretion of nuclear factor kappa B (NF-κB) and interleukin 6 (IL-6) and activates activator protein 1 (AP-1) and STAT3, resulting in significantly upregulated miR-21 expression and drastically enhanced cell proliferative and invasive capabilities.