PAX1,also named as HUP48,is a transcriptional activator. It may play a role in the formation of segmented structures of the embryo and may play an important role in the normal development of the vertebral column. It is a marker of the sclerotomal compartment. PAX1 was reported that,quantitative measurement of PAX1 hyper-methylation in cervical scrapings is highly sensitive and is more specific than HC2 in detection of cervical cancer. It is expressed by vSMC and pericytes during the earliest phases of vascular wall formation. This antibody is specific to PAX1.