MCM4 and salivary gland cancer: In previous study, MCM2, MCM3 and MCM4 were dysregulated in malignant salivary gland tumours [33], gastric cardiac cancer [34], thyroid malignancy [35], non-small cell lung cancer [36], malignant melanoma [37], colon cancer, promyelocytic leukemia [38], cervical squamous cell carcinoma [39].