NTRK1 and soft tissue sarcoma: Using an in situ proximity ligation assay, a lamin A/C (LMNA)-neurotrophic tropomyosin receptor kinase 1 (NTRK1) gene fusion encoding a functional LMNA-TRKA fusion oncoprotein was detected in the tumor of a 41-year-old woman with soft tissue sarcoma metastatic to the lung.