During the development of neurologic tumours or PNI in some nonneurologic tumours, the NGF/TrkA/STAT3 axis significantly facilitates the epithelial‒mesenchymal transition (EMT) of malignant cells (Meco et al. 2019; Lin et al. 2020; Guo et al. 2013). The gene discussed is NTRK1; the disease is neoplasm.