KLF4 and triple-A syndrome: Additionally, analysis of the correlation among EGR1, KLF4, and immune cells revealed that mast cells activated and plasma cells were significantly positively associated with EGR1, and macrophage M2 was significantly positively associated with KLF4. In contrast, macrophage M0 was negatively correlated with KLF4. Previous study has shown that TNF-alpha secreted by mast cells aggravated AAA and induced the formation of AAA in mice by secreting elastase (47, 48).