PDE6B and tuberculosis: Considering the fact that the RD1 region, which encodes components of T7SS including EccCb1, is the main distinction between vaccine stain BCG and virulent strains (Mahairas et al. 1996; Behr et al. 1999), the ATPase3 domain of EccC, especially MtEccCb1, is therefore a valuable target for developing new anti-TB therapies or vaccines.