CTSK and triple-A syndrome: In human AAA tissues, we also found that TPMs, when compared to myeloid cells, expressed more cathepsin K (5675 ± 1542 vs. 33604 ± 7540, p < 0.05) (Figure 7C) and MMP-9 (5444 ± 1891 vs. 27830 ± 5823, p < 0.05) (Figure 7F).