Plays an important role in mycobacterial pathogenesis in the context of innate immunity. Aids host cell invasion and intracellular bacillary persistence. Increases host oxidative stress response, leading to genomic instability and decrease in macrophage viability. Also induces autophagy and modulates the immune function of macrophages. Forms a complex with EsxP. Probably secreted via the ESX-5 / type VII secretion system (T7SS). Deletion mutant does not show any difference in intracellular survival and oxidative stress responses. Belongs to the WXG100 family. ESAT-6 subfamily.