TRIM24 and carcinosarcoma: We used chromatin immunoprecipitation (ChIP) PCR analysis of primary tumor cell lines and confirmed that TRIM24 was significantly enriched at regions of increased chromatin accessibility near −2.0 kb and the proximal promoter (−50 bp) of Met in the primary metaplastic carcinosarcoma line (897) but not the MMTV-Cre control (823) (Fig. 5c).