ID4 and soft tissue sarcoma: Notably, enhancers bound by EWSR1-ATF1 as well as TFAP2A, SOX10, and MITF were found proximal to genes such as MERTK and ID4 (Fig. 1e) that have previously been shown to be selectively expressed in CCS compared to other soft tissue sarcomas and melanoma29, as well as to many novel targets.