Considering the profound effect of DOT1L inhibition on proliferation of PEO1 and PEO4 cells that has been evaluated in our previously published study where we demonstrated that treatment of OC cells with DOT1L inhibitors EPZ004777, EPZ5676 and SGC0946 induced a concentration-dependent inhibition of cell growth in PEO1 and PEO4 cells [4], we investigated whether the interaction between the two proteins occurs also in this cancer type and to estimate the effect of their simultaneous inhibition on proliferation of OC cells. This evidence concerns the gene DOT1L and cancer.