FOXP3 and leprosy: This response is also analogous to a reversal reaction in leprosy (progression from lepromatous to tuberculoid leprosy), and is associated with a switch in the inflammatory balance from phagocytic to vitamin D-mediated antimicrobial macrophage function and clearance of mycobacteria.29 A reversal reaction is also associated with increased FoxP3 staining in lesions,30 consistent with the role of vitamin D in Treg differentiation, as well as influx of Th1 cells.31