NGF and Achalasia: On the other hand, mucosa from the proximal esophagus of achalasia had increased gene regulation in 12 pathways including those associated with leukotriene D4 metabolic process, degradation of extracellular matrix, NGF stimulated transcription, negative regulation of epithelial differentiation, positive regulation of tyrosine phosphorylation of STAT protein, angiogenesis, and Notch signaling pathway (Fig. 3e).