A similar synergism on the activation of intracellular kinases has been reported between leptin/IL-1 and leptin/IFNγ to activate NOS type II in chondrocytes, and a synergistic activation of ERK and EGFR has been associated with cell growth in oesophageal adenocarcinoma cells exposed to leptin together with acid [39–41]. Here, EGFR is linked to esophageal adenocarcinoma.