NTRK1 and endometrial cancer: NRGs includes four members (NRG1-4), among which only NRGI has been studied in detail.15 NRG1 is an epidermal growth factor (EGF)-like signaling protein expressed in a variety of tissues that acts as a ligand to bind and activate members of the receptor tyrosine kinase family (ErbBs), thus mediating multiple intercellular signaling.16 Li Wei suggested that the mRNA expression of NRG1 gene was diminished in endometrial cancer tissues, and the expression decreased with the increase of pathological grading and the progress of surgical pathology staging.