LEP and gastroesophageal reflux disease: For example, Murata et al. [138] showed that administration of leptin worsened reflux esophagitis in rats with evident infiltration of CD3 + T cells and a significant increase in the levels of macrophage inhibitory factor (MIF) and TNF-α, IL-1β, and IL-6 in esophageal tissue, the latter being considered as the downstream targets of MIF.