However, both PAD2 and 4 have been found to play crucial roles in the development of immune-mediated and/or neurodegenerative diseases due to calcium dysregulation and the detection of increase in deiminated proteins in the CNS is associated with numerous neurodegenerative diseases such as multiple sclerosis (MS), Alzheimer’s disease (AD) and Parkinson’s disease (PD) [16,17,18,19,20]. This evidence concerns the gene PADI2 and Alzheimer disease.