In cancer cells, aprepitant increases the sensitization of these cells to the cytotoxic action of determined substances (e.g., arsenic trioxide and vincristine); impairs the interaction of Forkhead box M1 with beta-catenin, leading to the blockade of the Wnt canonical pathway; arrests the G2 cell cycle (promoting apoptosis); activates the caspase 3-dependent apoptotic pathway; downregulates the expression of cyclin D1 and lymphoid enhancer-binding factor 1; and alters the DNA replication rate and cell cycle (Table 2) [89,90,91,92,93,94]. The gene discussed is CASP3; the disease is cancer.