The biological components, pyrimidine, glycoproteins especially mucin, oxygenated hemocyanin, and carotenoids showed differences in the three groups of saliva, normal (n = 21), premalignant (oral leukoplakia, oral submucous fibrosis, (n = 87)), and malignant (oral squamous cell carcinoma, (n = 50)). This evidence concerns the gene MUC5AC and Oral leukoplakia.