MAPK1 and decubitus ulcer: Hypoxic conditions in pressure ulcers result in increased cell death and release of toxic metabolites such as cyclooxygenase (COX)-2 and interleukin (IL)-6 through upregulation of extracellular signal-regulated kinase (Erk) and p38 mitogen-activated protein kinase (MAPK) [21,22,23,24,25].