TAT and neoplasm: The Tat system is involved in colonization, iron acquisition, and contributes to tumour formation of plant pathogens such as Yersinia pseudotuberculosis (De Buck et al., 2005; Lavander et al., 2006), Pseudomonas aeruginosa, Legionella pneumophila (De Buck et al., 2008) and Agrobacterium tumefaciens (Ding and Christie, 2003).