NOD2 and tuberculosis: MSCs are observed in and around human tuberculosis granulomas harboring MTB bacilli.222 MTB can be successfully hidden in BM-MSCs partly through the nucleotide oligomerization domain-2 (NOD-2) and Toll-like receptor (TLR-4) signaling pathways, and targeting MTB through NOD-2 and TLR-4 can be a useful method to eliminate the MTB concealed inside MSCs.223 Das et al.224 reported that MTB maintained long-term intracellular viability within human CD271+/CD45− BMSCs, which might be a therapeutic target for MTB persistence.