TPR and fibrosarcoma: TPR-NTRK1 fusion has been identified in infantile fibrosarcoma [8], pediatric papillary thyroid carcinomas [12], lipofibromatosis [13, 14], interdigitating dendritic cell sarcoma [5], fibrosarcoma-like uterine undifferentiated sarcomas [1], and colorectal adenocarcinomas (Supplementary file: Table 2) [15].