Emerging evidence has shown that abnormal expression of MELK might be involved in the tumorigenesis and progression of human cancers, such as prostate [17], breast [18], ovarian [19], oesophageal [20], gastrointestinal tract [21], and lung cancers [22], including chemotherapy resistance [14], stem cell renewal [14], and tumour growth [23]. The gene discussed is MELK; the disease is lung cancer.