In spite of the reduction in tumor volume, EPZ-011989-treated tumor samples excised from mice immediately or 15 days after the end of treatment showed an amount of viable tumor cells superimposable to that observed in untreated controls, although the proliferation rate, as detected by Ki67 index, was lower in treated compared to untreated samples (Figure 2C,D). This evidence concerns the gene MKI67 and neoplasm.