PLAGL1 and head and neck squamous cell carcinoma: The maternally imprinted PLAGL1 is expressed in normal tissues and downregulated in various tumors, such as breast cancer, ovarian cancer, nonfunctioning pituitary tumors, basal cell carcinomas, head and neck squamous cell carcinoma, and diffuse large B-cell lymphoma [3, 8, 30, 64].