CA125 (cancer antigen 125), also referred as mucin 16 or MUC16, is a member of the mucin family glycoproteins, encoded by the MUC16 gene. CA125 is a membrane-associated mucin that possesses a single transmembrane domain. A unique property of MUC16 is its large size. MUC16 contains about 22,000 amino acids, making it the largest membrane-associated mucin. CA 125 has found application as a tumor marker or biomarker that may be elevated in the blood of some patients with specific types of cancers, or other conditions that are benign. CA-125 is the most frequently used biomarker for ovarian cancer detection. CA-125 has been shown to play a role in advancing tumorigenesis and tumor proliferation by several different mechanisms. HER2 (Human epidermal growth factor receptor 2), also known as ERBB2, CD340 (cluster of differentiation 340), proto-oncogene Neu, is a membrane tyrosine kinase and has strongest catalytic kinase activity in HER family. Among four HER family proteins, HER2 functions as the most active signaling complex after dimerization with other members. It is encoded by the oncogene ERBB2, which is located at the human chromosome 17q12. HER2 participates in normal cell growth and found on some types of cancer cells. Its amplification is the major pathway causing HER2 receptor overexpression. HER2 is amplified in approximately 15%-20% of breast cancers and functions as the primary driver in breast tumor development and progression. The overexpressed HER2 is regarded as a valuable target in clinic therapeutics.