Proteins undergo post-translational glycosylation to generate serum glycoprotein, which makes up almost half of the total protein in serum. Similar to other forms of glycoproteins, serum glycoproteins are essential for a number of biological functions, including regulating the half-life of proteins in the blood, impacting the transportation of other proteins, altering immunological responses, and influencing various signaling pathways. An increasing number of human diseases have been linked to abnormal changes in the types and amounts of glycans and glycoproteins in human serum. Serum glycoproteins have been shown to serve as glycoprotein biomarkers for a number of disorders, including cancer, much like plasma glycoproteins.