Elevated PLK1 levels are associated both with good prognosis (e.g., in rectal adenocarcinoma, lung squamous cell carcinoma, and thymoma) and bad prognosis (e.g., in lung adenocarcinoma, bladder carcinoma, and kidney clear cell carcinoma) or are obviously not correlated (e.g., in stomach adenocarcinoma, cervical carcinoma, and ovarian cancer) depending on cancer type (reviewed by [149]). The gene discussed is PLK1; the disease is cancer.