EP300 and histiocytic sarcoma: In chimeric mice, loss of CBP or p300 leads to up-regulation of NOTCH1, BMI1, MYC, CCNE and SKP2 oncogenes, as well as the development of thymic lymphoma and histiocytic sarcomas 17-19, further confirming the role of CBP/p300 deletion/loss in tumorigenesis.