DEFB1 and infection: Bajaj-Elliott and co-workers assessed the role of β-defensin in the immune response of the gastrointestinal epithelium to infection by evaluating mRNA expression and regulation of human beta-defensins 1 and 2 (hBD1 and hBD2) by H. pylori in three gastric epithelial cell lines; MKN45, MKN7 and AGS using quantitative reverse transcription polymerase chain reaction (RT-PCR).