S100A8 and psoriasis: Moreover, authors found increased concentrations of two proteins known to play a role in a genetic predisposition to psoriasis and in the differentiation of keratinocytes: calgranulins A and B. On this basis, it was hypothesized that the overproduction of calgranulins may alter calcium homeostasis in the epidermis and lead to altered relocalization of cytoskeleton components and their abnormal proteolysis, as well as to immune responses against circulating cytoskeletal proteins.