CD9, also known as Tspan29, 5H9 antigen, Leukocyte antigen MIC3 (MIC3), Motility-related protein, is a multi-pass membrane protein which belongs to the tetraspanin (TM4SF) family or the transmembrane 4 superfamily. CD9 is a cell surface glycoprotein with 4 hydrophobic domains that is described to complex with integrins and other transmembrane 4 superfamily members. The protein takes part in cellular signal transduction events and thus play a role in the regulation of cell development and activation, growth and motility. Besides, CD9 seems to be a key role in the egg-sperm fusion during the mammalian fertilization processes. CD9 also seems to be a key part in the egg-sperm fusion during mammalian fertilization.

ABCC1 Protein, Human, Recombinant (His) is expressed in E. coli expression system with N-6xHis tag. The predicted molecular weight is 35.9 kDa and the accession number is P33527.

MDM4 (MDM4 Regulator Of P53, also known as MDMX) is a Protein Coding gene. This gene encodes a nuclear protein that contains a p53 binding domain at the N-terminus and a RING finger domain at the C-terminus and shows structural similarity to p53-binding protein MDM2. MDM4 is a promising target for cancer therapy, as it is undetectable in most normal adult tissues but often upregulated in cancer cells to dampen p53 tumor-suppressor function. MDM4, an essential negative regulator of the P53 tumor suppressor, is frequently overexpressed in cancer cells that harbor a wild-type P53. MDM4 is a key regulator of p53, whose biological activities depend on both transcriptional activity and transcription-independent mitochondrial functions. MDM4 binds to p53 and blocks its transcriptional activity.

Chemokine (C-C motif) ligand 6 (CCL6), also known as C-C chemokine C10 has only been identified in rodents, which is a small cytokine belonging to the CC chemokine family, beta-chemokine subfamily. C-C chemokine C10 is involved in the chronic stages of host defense reactions. C10 chemokine rapidly promotes disease resolution in the cecal ligation and puncture (CLP) model through its direct effects on the cellular events critically involved in host defense during septic peritonitis. CCL6 appears to contribute to the macrophage infiltration that is independent of other CC chemokines. C10 is a prominent chemokine expressed in the central nervous system in experimental inflammatory demyelinating disease, also acts as a potent chemotactic factor for the migration of these leukocytes to the brain. CCL6 may be a mediator released by microglia for cell-cell communication under physiological as well as pathological conditions of CNS. Additionally, the chemokine CCL6 may alter tumor behavior by relieving its growth factor dependency and by promoting invasiveness as a result of local tissue apoptosis.

The cluster of differentiation (CD) system is commonly used as cell markers in Immunophenotyping. Different kinds of cells in the immune system can be identified through the surface CD molecules associating with the immune function of the cell. There are more than 320 CD unique clusters and subclusters have been identified. Some of the CD molecules serve as receptors or ligands important to the cell through initiating a signal cascade which then alter the behavior of the cell. Some CD proteins do not take part in cell signal process but have other functions such as cell adhesion. CD9 is a member of the transmembrane 4 superfamily, which is also known as the tetraspanin family. CD9 is a cell surface glycoprotein with 4 hydrophobic domains that are described as complex with integrins and other transmembrane 4 superfamily members. It is found expressed on the surface of the exosomes. The protein takes part in cellular signal transduction events and thus play a role in the regulation of cell development and activation, growth and motility. Besides, CD9 seems to be a key role in the egg-sperm fusion during the mammalian fertilization processes. CD9 is found on the membrane of the oocytes and also appears to intervene in maintaining the normal shape of oocyte microvilli.