A2M and arthritic joint disease: However, since α2M has many functions it is unclear to what extent the arthritis-protective effects can be related to the direct inhibition of ADAMTS proteases or the interaction of α2M with inflammatory cytokines, such as IL-1β or tumor necrosis factor TNFα (Wollenberg et al., 1991; Legres et al., 1994; Rehman et al., 2013).