CTSS and triple-A syndrome: The roles of mast cells in AAA have been intensively discussed in Shi et al.’s review, that elevated proteases of mast cells like chymase and tryptase in patients with AAA, and these proteases contribute to leukocyte adhesion and migration, vascular smooth muscle cells (VSMC) apoptosis, foam cell formation, and expression of MMP and cathepsins (52).