NTRK1 and neoplasm: In seven patients aged 2–14 years with malignant or biologically indeterminate spitzoid tumors, RNA sequencing helped to identify a kinase fusion in five of the six sequenced tumors: TPM3-NTRK1 in two tumors, complex rearrangement involving TPM3, ALK, and IL6R in one tumor), BAIAP2L1-BRAF in one tumor, and EML4-BRAF in one disseminating tumor.