To investigate these mechanisms more precisely, MKN28 cells were treated with siRNA duplexes to silence expression of NFKB1 (which encodes the NF-κBp50 subunit), RELA (NF-κBp65) and MAPK1 for 48 h before infection with 60190 H pylori (figure 6A,B). This evidence concerns the gene NFKB1 and infection.