SSX1 and synovial sarcoma: Sixteen (rare) histological sarcoma subtypes were characterized by specific genomic events: a desmoplastic small-round-cell tumor harbored an EWSR1–WT1 fusion [12], an epithelioid hemangioendothelioma was characterized by a WWTR1–CAMTA1 fusion [13], an SS18–SSX1 fusion was detected in all three synovial sarcomas [14], a clear cell sarcoma had an EWSR1–ATF1 fusion [15], an NAB2–STAT6 fusion was present in two malignant solitary fibrous tumors [16], and an osseous spindle cell rhabdomyosarcoma was defined by an FUS–TFCP2 fusion [17].