MAPK14 and infection: Macrophages recognize pathogen-associated molecular patterns (e.g., lipopolysaccharide (LPS)) and damage-associated molecular patterns (e.g., adenosine triphosphate (ATP) and nigericin) by pathogen recognition receptors (e.g., toll-like receptors (TLRs)) and subsequently activate the downstream mitogen-activated protein kinases (MAPKs, such as the c-Jun amino-terminal kinase (JNK), the extracellular signal-regulated protein kinase (ERK), the p38 MAP kinase (p38)) and transcription factors (e.g., nuclear factor-κB (NF-κB)) to regulate immune responses against pathogen infection [8,9].