For example, the polymorphisms of the chemokine C-C motif ligand 4 (CCL4) gene influence gene expression and protein function and predict risk and prognosis of various diseases, including hepatocellular carcinoma, oral cancer, and psoriasis [12–14].The CCL4 belongs to a cluster of genes located in the chromosomal region 17q11-q21. The gene discussed is CCL4; the disease is psoriasis.