SPP1 and triple-A syndrome: •AAA aortas had reduced SMC cell density, increased macrophages, and reduced percentage of fibroblasts. The largest cell population within AAA tissues were fibroblasts•Cebpb (encoding for basic leucine zipper transcription factor CEBP-B) was the most upregulated gene in AAA; Spp1 (encoding osteopontin) showed largest fold increase compared to sham•Macrophages were composed of 3 distinct populations; Mø-1 demonstrated an anti-inflammatory gene profile, Mø-2 shown a classic inflammatory profile, while Mø-3 had enriched proliferation pathways