Yoshida A, Arai Y, Tanzawa Y, et al. - Using a combined histological and molecular approach, researchers intended to describe unclassifiable sarcomas. In-frame fusions involving KMT2A (MLL) in two cases were identified via RNA sequencing. RNA sequencing identified a YAP1 (exon 5)–KMT2A (exon 4) fusion in case 1 and a VIM (exon 4)–KMT2A (exon 2) fusion in case 2, both validated by reverse transcription-polymerase chain reaction, Sanger sequencing, and fluorescence in-situ hybridization. In young adults, KMT2A fusions accounted for a subset of aggressive unclassifiable sarcomas. It was presently not clear if these sarcomas belonged to a single group, but the well-established part played by KMT2A fusions as drivers of acute leukemia and a current study about the recognition of YAP1–KMT2A in one unclassifiable sarcoma supported the importance of these fusions.