As an indirect mechanism, MCs release IL6 and IFN-γ after activation to induce vascular SMC and EC expression of cysteinyl cathepsins (Sun et al, 2007b), which also participate in arterial wall remodeling and AAA pathogenesis (Sun et al, 2011, 2012; Qin et al, 2012). This evidence concerns the gene IL6 and triple-A syndrome.