However, carbamylated collagen lost the ability to stimulate neutrophil oxidation through LFA-1 integrin and Focal Adhesion Kinase (P125FAK) signaling pathway, which was known to be involved in the development of inflammation and infection,19, 20 thus, protein carbamylation reaction causes skin aging changes, such as loose skin, wrinkles, and inflammation. Here, PTK2 is linked to infection.