It has been reported that defects in the signaling of small G-proteins such as Rac1 and Cdc42 can affect insulin secretion,[37] and small GTPases such as Arl8b, Rac1 and several Ras-associated small GTPases have critical functions in the host immune response against tuberculosis.[38–40] Therefore it is highly possible that small GTPases may be involved in the pathogenesis of DMTB. This evidence concerns the gene CDC42 and tuberculosis.