Creative Biolabs is a world-leading company offering custom-specific development services of high-quality in vitro diagnostic (IVD) antibodies for the diagnosis of a diversified battery of diseases, including autoimmune diseases, cancers, infectious diseases, and cardiovascular diseases. Particularly, we offer antibody development services for diagnostic uses targeting PAD type 4 (PAD4) as a promising biomarker for the diagnosis and prognosis of rheumatoid arthritis and cancers.

Introduction of PAD4

PAD4, also known as peptidyl arginine deiminase type 4, belongs to a calcium-dependent family of enzymes. It is a 74 kDa enzyme and consists of 663 amino acids. PAD4 is highly expressed in a range of cells, including T cell, B cell, and macrophages. Functionally, it is responsible for regulating the immune responses of granulocyte and macrophage. Studies have revealed that PAD4 can mediate the protein citrullination in a wide variety of cells, such as neutrophils and monocytes. Meanwhile, PAD4 is associated with many biological processes, such as cell differentiation, apoptosis, and the catalysis of nuclear proteins. Furthermore, it also plays an important role in neutrophil extracellular traps (NETs) formation and the inflammatory response of granulocyte.

PAD4 as a Marker for RA & Cancers

PAD4 has been considered as an important indicator for diagnosis and prognosis of both RA and cancers. Firstly, researchers have indicated that the expression of PAD4 at mRNA or protein level is significantly high in a number of cancers, particularly in adenocarcinoma. Secondly, it was reported by E Witalison et al. (2015) that PAD4 played a pivotal role in the pathogenesis of RA through citrullination of extracellular proteins, neoantigen formation with mounted an immune response and a vicious circle of the disease in those genetically pre-disposed. Moreover, anti-PAD4 autoantibodies have been reported in approximately 50% of patients with RA. The sensitivity of and specificity of these autoantibodies for RA diagnosis have also been identified in a wide variety of preclinical and clinical trials.

The immunodetection of PAD4. Fig.1 The immunodetection of PAD4 (A, C) in ovarian tissues. (Chang, X., 2006)

IVD Antibody Development Services for PAD4 Marker

Due to the fact that PAD4 is strongly associated with a number of diseases, including several cancers and RA, IVD antibodies against PAD4 can be developed to help the prognosis and diagnosis of these diseases. At Creative Biolabs, we provide polyclonal, monoclonal, and recombinant antibody development services for diagnostic applications. With our versatile IVD platform, Creative Biolabs is proud to develop novel PAD4-specific antibody with high specificity and affinity. Moreover, we also offer immunoassay development services, including enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and western blot, for both research and diagnostic applications.

Creative Biolabs is a forward-looking research institute as well as a leading custom service provider in the field of IVD antibody development. Backed by a team of seasoned scientists, we are capable of providing our clients with the most professional and sophisticated services. If you are interested in our services, please contact us for more details.


  1. Chang, X., (2006). “Expression of peptidyl arginine deiminase type 4 (PAD4) in various tumors.” Mol Carcinog, 45(3), 183-96.
  2. E Witalison, E., (2015). “Protein arginine deiminases and associated citrullination: physiological functions and diseases associated with dysregulation.” Current drug targets, 16(7), 700-710.

Online Inquiry

*E-mail Address:
*Service & Products Interested:
Project Description:
*Verification Code:
Please input "biolabs"(case insensitive) as verification code.

Contact Us

45-1 Ramsey Road, Shirley, NY 11967, USA
Tel: 1-631-381-2994
Fax: 1-631-207-8356

Follow us on:
Copyright ©2011 - 2019 Creative Biolabs.