MYLK and triple-A syndrome: Smooth muscle cell (SMC) contractile elements, such as smooth muscle actin (a-SMA) [8], myosin light-chain kinase (MLCK) [9, 10], and smooth muscle myosin heavy chain 11 (SMMHC11) [11, 12], and other gene mutations are related to the occurrence and development of AAA, and it has been found that it may trigger the phenotypic transformation of SMC.