CD4 and tuberculosis: Bergenin is a natural compound extracted from fresh leaves of the genus Bergenia. It activates the MAPK, ERK1/2, and SAPK/JNK pathways in Mtb-infected macrophages, selectively induces the secretion of IFN-γ, TNF-α, IL-12, IL-17 expressed from CD4+ and CD8+ T cells, and promotes NO production for the clearance of Mtb in mouse TB models (Kumar et al., 2019).