HCST and triple-A syndrome: We studied the protein expression of nine different members of the NK Cell Mediated Cytotoxicity Pathway (VAV1, VAV3, PLCG1, PLCG2, HCST, TYROBP, PTK2B, TNFA, and GZMB; Figure 1) in human AAA and compared the results to aortic tissue samples taken from the infrarenal aortae of age- and sex-matched controls (Table 1).