Examining this connection further, another study using an obese asthma mouse model found that elevated leptin levels worsened airway inflammation by promoting inflammation through extracellular signal-regulated kinase (ERK) 1/2, p38 mitogen-activated protein kinase (p38-MAPK), MAPK kinase (MEK) 1/2, and NF-κB signaling pathways, pathways that are targeted to enhance inflammatory responses [14]. This evidence concerns the gene LEP and asthma.