PRL and systemic lupus erythematosus: In this sense, it has been proposed that the APCs can block Treg cell activity via overproduction of pro-inflammatory cytokines such as IFNα.42 It would be interesting to determine whether APCs express PRL receptor, and whether PRL favors the secretion of IFNα and other inflammatory cytokines, thereby aiding the malfunction of Treg cells in SLE patients.