Enhances mycobacterial intracellular survival, probably via altering host macrophage cytokine profiling and attenuating the cell apoptosis (PubMed:27987050). Could be required for host endothelial-cell invasion (PubMed:16586367). Expression in Mycobacterium smegmatis, a nonpathogenic species naturally deficient in PE_PGRS genes, results in alteration of the production of host cytokines, including IL-6, IL-1beta, IL-10 and IL-12p40, as well as enhanced survival within macrophages largely via attenuating the apoptosis of macrophages. Cell envelope-associated protein. Highly up-regulated during the early stages of invasion of the human blood-brain barrier. Invasion of the infant human brain microvascular endothelial-cell monolayer is significantly decreased in transposon mutant. Belongs to the mycobacterial PE family. PGRS subfamily.