Oral cancer has a high mortality rate, making early diagnosis crucial for effective treatment and prognosis. Unlike other cancers, oral cancer develops in the oral cavity, enabling direct contact between saliva and cancer cells. Therefore, saliva is a more useful diagnostic tool than serum or tissue. When DNA, RNA, or proteins produced by cancer cells enter the saliva, they can be easily detected as tumor markers. Therefore, salivary biomarkers can serve as a noninvasive alternative to serum- or tissue-based biomarkers. Early diagnosis is essential for increasing the treatment success rate, improving prognosis, and enhancing post-treatment recovery, ultimately improving the quality of life. Proteins are essential molecules involved in key processes, such as the development, growth, death, and metastasis of oral cancer. Recent advancements in molecular biology and salivary proteomics have enabled the detection and analysis of numerous proteins in saliva. Many of these protein molecules are currently the focus of extensive research. This article aims to review the potential of saliva as a diagnostic tool, techniques for detecting protein biomarkers, and salivary protein biomarkers for oral cancer diagnosis.

Introduction
Saliva as an Alternative Diagnostic BodyFluid
Saliva Proteins and Analysis Techniques
Salivary Biomarkers for Oral Cancers
    1. Enzymes
    2. Cytokines and glycoproteins
    3. Cluster of differentiation
    4. Others
Funding
Conflicts of Interest
References

• Jeong Hee Kim(Department of Oral Biochemistry and Molecular Biology, College of Dentistry, Kyung Hee University, Seoul 02447, Republic of Korea, Department of KHU-KIST Converging Science and Technology, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea) Corresponding author
• Joungmok Kim(Department of Oral Biochemistry and Molecular Biology, College of Dentistry, Kyung Hee University, Seoul 02447, Republic of Korea)