YF2 is equivalently cytotoxic in TCL cell lines with IC50 ranging from 4.4 to 14 uM compared to the IC50 values in EP300 mutated BCL lines (5 to 11 uM). Additionally, YF2 induces apoptosis and G1 arrest in a dose dependent manner demonstrated by flow cytometry. We collected three primary lymphoma patient samples including one FL sample carrying CREBBP and p53 mutations and observed that YF2 induced cell death in patient samples, but not in PBMCs from 3 healthy donors, indicating a good therapeutic window. Robust synergy with combination of YF2 and romidepsin was observed in 100% (6/6) EP300 mutated BCL, 40% (2/5) EP300 wild-type BCL and 60% (3/5) TCL cells (EOB = 28).