Consistent with PLK1’s biological role in cell cycle regulation, PLK1 overexpression has been observed in a variety of cancer types, including melanoma, breast, non–small cell lung (NSCLC), colorectal, prostate, pancreatic, ovarian, and head and neck cancers, as well as non-Hodgkin lymphoma (NHL) and acute myeloid leukemia (AML) [10]. This evidence concerns the gene PLK1 and cancer.